Framing 101 Topics
It is what you can’t see that matters the most!
Picture and Art Framing serves two important functions, Preservation and Presentation. Everything that is done supports one or both of these goals.
To ensure the longevity and durability of your works of art. Whether an original oil or acrylic painting, a watercolor, a signed and numbered print, or your child’s first masterpiece.
The ultimate goal is to preserve the piece for as long as possible in relationship to the value of the work. This includes reducing environmental damage and effects as much as possible. Sunlight, indoor pollution, excessive changes in humidity wet or dry can all damage the artwork and frame.
Proper presentation can dramatically increase the esthetic appeal and emotional attraction and connection to the artwork. It just looks better and it’s value is increased.
Poor or improper framing takes away from the appeal of the artwork. It doesn’t look good and it’s value is decreased.
With both Preservation and Presentation there should be a common sense balance between the artworks value (emotionally and financially) and what is spent on the framing.
The intent of this information is to give you simplest possible explanation of framing. Its not meant to be a book, or teach you to be a great framer, although if you do read this, you will have a better understanding of good framing than many framers. I did not take it from any books or sources about framing but it is condensed from my 35 years of wood working experience, and what I have learned about framing. I will be simple to understand, and if you have any questions you are always welcome to contact me.
What is proper design? However many people you ask, is about how many different answers you are likely to get.
The simple answer is .
* Framing allows the transition from the surrounding environment into
* It provides structural support for the artwork. *It allows for
additional protection through the use of glazing.
* It provides the mechanical method of attaching the art to the wall or
So what is good framing?
How would I know it if I saw it?
Now it get complicated. There is the structural integrity of the frame, and the components in what is called the package. That would include, the Art, glazing if used, backing material, matting, or liner, and spacers. Much of this you can't see, because it is sealed and hidden when the project is completed. I will address this later.
The next element is visual. This is affected by different tastes, and economic factors.
* What your influences have been, what your personal sense of style is.
* Where the artwork will be displayed.
* What is your connection to the artwork, what value you place on it. .
* How long do you plan on keeping or displaying it.
While all of these factors, and many more affect your choices, there is one constant. Mechanics. This has been overlooked by every source I've found. It is said that everyone sees thing differently. Is that really true? I promise this will all make sense and feel logical. You might not have ever though in these terms before, I know few in the art world have. But the eye's function mechanically. They react predictably in many given circumstances.
Our eye's are attracted to what reflects the most amount of light. Lighter colors, reflect more light than darker colors. Our eye's see them more easily, they “stand out” more. Contrasts in color also get our eye's attention. Light Vs dark, brighter colors Vs softer muted colors. Strong, dark, bold, or dense colors are harder for the eye's to overlook. Even depth and dimension affect what and how we see. An object closer to our eye's will tend to be seen first.
How this affects framing? Well designed framing will allow our eye's to naturally transition from the environment, to the frame, moving inwards to the artwork, and the central intended focus of the art itself.
Naturally - what do I mean by naturally? That the eye will do it without thinking. It will allow the subconscious mind to see it as a whole, be attracted or drawn to it, and start the process of appreciation or recognition.
Its not a question at this point of large, or small. Simple or complex. Its how integrated is the framing and the art, how well does it work in unison. Do your eye's get stuck at any of the elements. Do they get pulled away from moving easily towards the intended focus of the art.
Case in point: If you have a dark or soft piece of art, and you choose light or bright colors in the framing or matting. Your eye's will be pulled to the lighter colors, away from the intended focus of the art itself. You have to force your eyes to see past what they see most easily.
Colors are more a selective response, tied to our own preferences. But how our eye's react to them, and the contrast are more universal. With the exception of forms of color blindness, and how the brain process what the eye's see.
Re-writing the book a bit
Case in point. I'm sure you have noticed that when you go to Museums, Galleries, and Art shows or contests, that the matting is almost always white? Why ? Is it because it's what's best for the art and presentation. The answer will step on a few toes, because it is universally thought the answer is yes. Well, it really isn't.
* Museums choose white when they choose to mat something because
they want you to see the Art, not the presentation.
* Galleries choose white, because they are there to sell you the Art. They
don't want to risk choosing a color that someone might not like and risk
loosing the sale. Are they being as safe, neutral, and Vanilla as
possible. You betcha, if the customer doesn't like it, they can reframe it
themselves. It's just the Nature of the business. Keep the costs low, the
profits high, and give the customers the least number of reasons to
object, or not to buy as possible.
* Art shows, and this includes photography. When the shows are being
judged, most of the time they don't want the presentation to enter into
the equation. You might not know it but many time the work is judged
by slides taken with a camera of the Art with no consideration of the
framing or presentation. They are critically judging the work for style,
technical merit, use of the medium, in other words how it compares to
other work in its field.
So what happens with that bright white mat around the image? Whether you know it or know or not, your eye's are having to work to see past the white. Don't believe me. Next time you look at something with a bright white mat, hold you hands to form an aperture or opening. Look at the piece without your hands up, then cover the matted area with your hands and see if the image isn't easier to see. I'm not saying it is wrong to use white. I'm saying that while the color may be neutral, the mechanical affect it has isn't. Black and White photography responds well to white matting.
Use white when it works for the piece, when it is the right choice for the presentation. Obviously if the rules or regulations require it, you don't have much of a choice.
The other side of the coin
Black frames. OK watch your toes again. Its the other side of the mechanical equation. Those black plasticy coated and painted frames are so dark and dense, they can easily over power the presentation.
They create a heavy intimidating border around the piece. And if your eye's see it to strongly, again they have to work to look past it. Again like the white, am I not saying “don't use black”. No not at all, if it is the right choice use it. There are options, a number of black frames have a visible grain pattern to soften the feel of the black.
Dark gray's and Brown's can give the feel of black but be softer and less harsh. Think of the warm soft tones of coffee beans, the ones that have been roasted for an extra long time. Soft, warm, earthy, and rich, compared to Black Plastic. All I'm saying is that for to long, the framing industry pushed Black because it was a quick easy choice. That is once they convinced the pubic it was a one size fits all, right for everything choice. Black is bold, edgy, contemporary, and many times it is the perfect choice.
The bottom line.
It should all work in harmony, in balance. From extreme to subtle. From soft and muted, to bright and bold contrasts. Art reflects nature, and nature has very few limits. Once you own the Art, it is your choice. The Art now has unlimited potential, from one edge of the frame to the other.
There are no real rules when it comes to your tastes, no one has a right to tell you you're wrong if you truly like it.
Bottom line, you're paying for it, it will be in your space, its your choice, period. If your framer doesn't honor and support your choices, and your tastes, find another one.
Framing should be fun. You should enjoy the process. When it is done, you can stand back and revel in your accomplishment. It is everyone's chance to be an artist, well, at least have a hand in producing the finished product.
I have heard countless customers say, “I don' know anything about art and framing”. The best advice I can give, is that you know what you like, and if not, what you don't like.
Give yourself permission to explore, express, to play. The expression “think outside of the box has been used to death” but all it is saying is feel free. Free to choose what pleases you.
How can I tell when we've gotten it right. When I show it to the customer(s), and it get's really quite, and I see their smile(s).
The frame provides two important functions, Structure and Esthetics.
Structure: the frame provides the structural element that supports the artwork physically. In a canvas work, it provides additional strength to the stretcher bars. Helping the stretcher bars to resist twisting and warping, keeping the artwork straight and flat. The frame also provides a measure of protection to the outside edge of the canvas.
If the frame is to incorporate glass, matting, and fillets, the frame provides the structure to hold and align the completed package. Structurally the frame also provides the mounting points to attach whatever method and hardware will be used to secure the artwork to the wall structure.
Esthetics: A properly selected frame provides for a pleasing transition from its environment (the room) into the central focus of the artwork. Properly done, the frame welcomes and guides the eyes from the wall, to the frame, and into the intended focus of the work of art.
Improperly designed, the flow of the viewer’s attentions is distracted from the artwork. The frame attracts or distracts the viewer’s attention, the viewer sees the art, but is drawn back to the frame away from the intended focus of the artist. This action forces the viewers eyes to wander back and forth, instead of consciously enjoying the balance and integrity of a well-designed and pleasing work of art.
Custom framing allows the work of art to be tastefully integrated into its environment. Bringing together elements of the materials, colors, or textures of its surroundings. It can make a bold and dramatic statement, or blend subtly into the background.
Wood frames are constructed of a natural product, from various varieties of trees from around the world. While all the manufactures struggle to use materials that make their molding as stable as possible.
By nature wood is Hygroscopic, it absorbs and releases moisture. As it absorbs moisture is swells slightly, and as it releases moisture it dries, allowing it to shrink, again very slightly. This is constant and varies with the seasons.
Here in New Mexico it is more extreme, from the dryness of our winter, to our summer where the indoor humidity is increased by our evaporative (swamp) coolers and the Monsoon season.
This drastic extreme in humidity changes wreaks havoc on wood products and furniture, as its swells and contracts time and again over many years.
Cutting the Molding
The simplest and standard way to cut the molding to the proper size is to make one cut. Separating the pieces, creating the forty five degree angles, and creating the finished leg. What I found was that if there was any warpage, bowing, or twisting, the cut would not be at a true forty five degree angle. This results in a corner where the to angles do not come together cleanly and tightly. While mostly an esthetic concern, the resulting gap must be filled with a material called putty. This increases the eyes attention drawn to the joint, detracting from the visual appeal of the frame and the artwork. The other problem with putty is that it is not elastic and once compressed it will not expand. So when the frame swells the putty compresses and then when the frame contracts again it leaves the open gap again.
To reduce or hopefully eliminate the problem of inaccurate cuts and the resulting marginal corners, I first separate the full length of the molding from the length being sized for the leg. I then make additional cuts to true up the angle to a perfect forty five degrees. The legs are then sized to a tolerance of within about a hundredth of and inch of the desired size.
The goal is to eliminate the need to add filler or putty to the face of the frame, making the frame as perfect as possible. Many times due to the design and manufacture of the chosen molding the outside edge will still require some attention and filler . However it is far less noticeable than on the face or front surface.
To help make the joint even less noticeable, when possible the cut diagonal surface is colored. This is done in an effort to match the frames original finish as closely as possible. In this way if the side or edge of the molding is visible it will match the rest of the molding making the joint as invisible as possible. You don’t want anyone’s eyes to be drawn to unsightly joints in the corners.
Once you have seen the difference you will forever appreciate the extra effort.
The corner and structural integrity:
In almost all picture framing the corners come together to form four ninety degree angles. This is accomplished by creating forty five degree diagonal angles in the molding and joining them together to form the ninety degree corners. If the corner angles are completed correctly you will have an accurate 90 degree corner, and if the molding is straight, the four accurate corners combined will produce a perfect frame.
In a perfect world this would be true, but wood is a natural product and is rarely perfect even before you add in the effects of changing humidity.
So what does all this mean to you, your artwork, and your choice of frames. Lets start with nature, and its effects. When wood absorbs moisture it swells (expands) its does so along its length and its circumference. The angles are cut diagonally across the grain of the wood, so as the wood swells it will expand at varying rates across the surface of the diagonally cut molding.
This causes stresses in the joint as the expanding forces oppose each other. Even though this happens on a very small scale, it remains a concern.
How the joint is constructed.
Assuming the opposing diagonal cuts are prepared accurately, the joint must be held together. In traditional framing the conventional wisdom has been that glue or an adhesive provides the bond to hold the corner together. As glues or adhesives have evolved their strength and moisture resistance have increased.
Starting as mixtures made from boiling and processing animal hides, evolving into today’s high strength wood glues. The strength or bond that a glue creates is dependent on the amount of surface area of the product the glue is in contact with. Obviously this is determined by the area of the opposing diagonal surfaces, but it has another very important factor
Porosity, wood is a porous material, it has small pores all through its structure. The more porous the wood the more open the surface, the less porous the wood the smoother the surface.
The affect this has on the joint is that the glue can soak into the pores of the woods surface. In effect increasing the amount of surface contact, just imagine tiny little fingers of glue spreading out from the surface of the glue deeper into the wood. The more porous the wood the stronger the joint or connection.
Now for the problem, as the wood creating the joint expands and contracts at different rates, there are forces generated. As it contracts it tries to pull apart, and as it expands it tries to push apart. If that wasn’t bad enough, being at right angles to each other, the pores and fibers move side to side in relationship to each other. This creates a shearing force on the glue joint. All this movement weakens or breaks the glues bond with the two surfaces causing the joint to fail.
So what can be done, in traditional framing nails are used There are pilot holes are drilled in the side of the molding. Then the nails are inserted. In some cases a nail gun is used to shoot the nail into the wood. Most people in the industry will say the nails are only used to give the glue a chance to set up (dry).
Another option is to place the two pieces in a vice to let the glue set up and then be nailed. Once the frames finish has be violated, it has to be touched up or repaired. Even in the best of circumstances this leaves the holes visible. Nails have another problem, their strength, or holding power is determined by their own strength and the amount of surface area they come in contact with. Which for a round thin nail is very limited.
Recently a new product has been developed, a V-nail or wedge nail. It is inserted into the joint from the underside. This provides strength directly at the source of the joint and does not damage or mar the finished surface of the molding. If you don't alter or drill the finished surface, you don't need to repair or touch it up.
Unfortunately clinging to the belief that the glue provides the strength and holds the joint together, framers have used the V-nails to again “hold the joint together while the glue dries” and only use one or two.
Starting from scratch, I decided to see if the traditional systems and methods could be improved upon. I found that the V-nail could be incorporated as a structural element on several levels.
By inserting the V-nails along the entire length of the diagonal joint it mechanically holds the two surfaces together.
Much like a thread holding a seam together between two pieces of fabric. By tightly holding the two sections together there is far less movement between the two sections and thus the glue joint maintains its integrity more readily.
The other benefit to what I found was that by using the longest possible V-nail, the area of surface contact and strength provided by the V-nail was extended from the underside of the frame deeper, or further up into the crown or front surface of the frame. This helps the frames corners resist twisting forces applied to the joint.
As with all engineering applications the trick is in the balance, to few V-nails and the surfaces can open up, two many and you run the risk of damaging the integrity of the woods fibers and actually weakening the material and the joint.
To short a V-nail ,and the V-nail doesn’t extend deeply enough to resist possible twisting. To long a V-nail and you run the risk of deforming, or damaging the frames surface and appearance.
As you will see from the visual demonstrations great care and effort are given to the choice and application of this system.
Whenever possible I will produce a test corner prior to assembling the customer’s actual frame. The V-nail machine is set up for each size and style of molding. The test piece is joined without glue and broken open to verify the results of the setup and installation and placement of the V-nails. This allows me to maximize the strength and integrity of each joint, corner, and frame.
Is all this effort overkill? Like many industries, people resist change. Those that have been doing it the “old way”, say its been that way for 100s of years, why fix what isn't broken. I feel that is limited thinking. Technology allows us to constantly improve our materials, methods, and products.
After a frame has failed and fallen off the wall, is not the time to think, now its broken, what can we do to fix it! Make it the best and strongest from the beginning.
Admittedly some others are impressed, but always ask “why do you do it when no one will ever know, and nobody else bothers”.
So why do I do it? It takes me two to three times longer to create a frame than the traditional way of framing. As a businessman I fully understand that time is money.
So how important is it to me, I could not and would not think of doing it any other way. As a perfectionist there is only one way to do things the right way. What is the right way? Do it the best way you know how, period.
As for you the customer, does it matter?
You will have to make that decision your yourself. I go through all the extra effort for the customer who can appreciate quality. Quality in the ultimate form of longevity, in protection, in appearance, and in value.
The bottom line is, if you could have the very finest produced frame and not pay any more for it, why wouldn’t you choose it.
Glass or Thermoplastic
There are two main materials used in glazing, Glass and Thermoplastic or Polymers. The thermoplastics or polymers commonly called Plexiglass consist of many different “Brand” names. Some you might have heard of are Plexiglass now called Acrylite, Lucite, and Lexan to name just a few. They are Acrylic and Polycarbonate sheets. Both Glass and Polymer sheets come in different thickness, and different properties that will be covered in detail below.
The primary purpose served by the glazing is to reduce the potential damage to the artwork by the environment. This includes, direct and indirect damage. Direct damage, would be contact with physical objects striking the surface, including liquids. Indirect damage or environmental damage, would include smokes, gasses (air borne pollution), cooking oils and greases, and excessive humidity, such as near bathrooms or in areas with evaporative coolers that increase the humidity to excessive levels.
Somewhat recently another culprit has been added to the list, this is the most destructive of all, light. This includes natural sunlight, fluorescent, and incandescent lighting. The culprit, UV or the Ultra-Violet rays of light in the previous light sources. UV causes a break down of the pigments, inks, or dyes in the artwork and matting materials. This results in fading and discoloration of the materials. Standard glass and plastic sheeting will filter out approximately 30% of the UV transmission through the glass.
Recently a new product has been added to reduce the damage from UV exposure, Conservation glazing. This glazing has a filtering agent added to reduce UV transmission. The reflection, or rejection rate is about 70 to98%, greatly reducing the damage.
Investing in conservation glazing is the best and cheapest insurance you can provide for your artworks longevity, and your long-term enjoyment.
Glazing and appearance or esthetics
The type of glazing can also be influenced by the need to control glare, or light and image reflection. Light and images can be reflected by the surface of the glazing the same way as in a mirror. This can be detrimental to the presentation and enjoyment of the artwork by reducing your ability to clearly see the image of the artwork. There are several options that can be chosen.
Non-Glare Glass: This is a glass that has the outside surface etched to reduce the reflection or glare. It also has a softer somewhat fuzzy look to it. Care must be taken not to separate the glass from the works surface to far or the image will become cloudy or appear out of focus. Non-glare glass can also be used as a design element by softening up the image on purpose.
Non glare is also available with conservation, UV protection. Thermoplastic sheeting is also available in a non glare form with a matt appearance.
Museum or Anti Reflection Glass: This glass has a process applied that breaks up the light being reflected off of the surface of the artwork. This is somewhat complicated to explain but the glass seems to just disappear. It does not get fuzzy or cloudy and is great for displays or shadow boxes where perfection in optical clarity is required. There is some reflection off axis, at an angle. But is as good as it gets.
The thermoplastic has something they market as competition to Museum Glass, but due to the wavy optical distortion, it just doesn't seem as clear to me.
The Thermoplastic or Polymer sheeting
These products are available with the same properties as glass. UV protection, and glare or reflection control. These products are generally much more expensive than glass with equal properties. The sheeting used for picture framing is refereed to as “Framing or Museum Grade”. It is not the material used for the very thin storm windows at the building supply stores. Some big box stores will use that for very inexpensive ready to hang art. It just isn't suitable for quality picture framing.
There are different grades of sheeting referring to the level of inclusions. Inclusions are impurities in the material. They can be small air bubbles and foreign materials in the plastic itself.
For example; Acrylite gives their better grade sheets the designation FF. It comes off the same production line, its just the sheets that are supposed to be free from inclusions. The sheets with inclusion are rated differently, and might be used by signs companies, glass and window companies, and framers who are less concerned about quality than profit.
Glass Vs Thermoplastic / Polymer or Thermoplastic
The advantages of Thermoplastic and Polymer sheeting -
+ Lighter than glass for the same thickness material.
+ Is available in a larger sizes than glass.
Normally stocked in 48”x 96” but can be ordered in 60”x120” for
a rather large price.
+ Required by building codes in some circumstances. Healthcare,
Mental health and correctional facilities.
It doesn't form the sharp edges usually formed by broken glass.
+ Is much more durable and and less likely to break than glass.
Potential vandalism by customers and visitors is reduced. Many
Museums prefer it for this reason.
As in the building codes safety. For over active or excited children
and adults, Frisbee's, balls of various sizes, shape's and degrees
of surface strength.
The disadvantages of Thermoplastic and Polymer sheeting -
- It does not stay perfectly flat like glass and visually can have a
wavy pattern, or distortion in the appearance.
In severe cases it can bow or curve in either direction over time.
- It scratches easily. The outer surface is literally starting to
degrade from the moment the protective
coating is removed. It can be seen as very tiny swirls, that looks
like a fine spiders web when seen in the light.
To larger side to side, or up and down scratch patterns. Most of
these are caused during attempts to clean the surface.
*Dust on the surface acting as an abrasive.
*The wrong kind of cleaning material or cloth used, acting like fine
*The wrong cleaning chemical, cleaners not designed for plastics.
Cleaners or Polishes that have abrasives in them.
While good for some situations, are very hard to control and use on
large sheets of glazing.
Swirl marks and patterns will be seen in the reflection of point
sources of lights, track lights etc.
- Cost. As mentioned earlier, it is much expensive than glass when
using “Framing Grade” sheeting.
The advantages -
+ It stays perfectly flat. With virtually no visual image distortion.
+ It is much more difficult to scratch, or cause damage to the optical
+ It is much less expensive than thermoplastic.
The disadvantages -
- It breaks more easily. Safety and transportation concerns.
- It is heavier than glass. This isn't usually an issue.
- It is only available in picture framing glass up to 40”x60”.
Anything bigger is to thick and heavy to use in framing.
The original purpose for incorporating a mat into artwork was to provide a space between the surface of the artwork and the Glass (glazing). Significant damage can occur when the Glass and the artwork are in direct contact with each other. The inks or pigments can transfer (stick) to the glass, and mold or mildew can form more easily without an airspace.
The original mats came in the soft neutral colors of the materials they were made from. It was was also believed that the soft whitish colors would not conflict with the artwork. However over the years mats have evolved and colored mats have become design elements used to enhance the overall presentation of the artwork. With the variety of colors, textures, and fabrics currently available in mats, the skies the limit to your creative possibilities.
Mats are made of several materials, predominantly cellulose or paper mats and cotton or Rag Mats. The danger and concern with regular paper or cellulose mats are that they contain chemicals or substances that are very harmful to artwork.
“Plain” Paper mats are made from wood pulp or cellulose. They have components that are acidic and can cause damage to the surfaces they come in contact with. Damage can also be caused by off gassing, or the materials releasing harmful gasses or vapors. The quantity is very small and in no way is hazardous to our health but not so for your artwork. There are other substances (lignin) in paper mats that cause them to discolor the white bevel cut edge turning it to a dingy brown color.
The damage to the artwork is referred to as a burn and will appear as a darkening of the artwork starting with the area of direct contact.
Alpha Mats or Alpha Cellulose mats. Here is where it gets more confusing. The industry will “say or claim” Alpha mats to be “Acid free”, “PH Neutral”, “Buffered”.
If you remember a bit of basic chemistry, you may already be thinking that this is in conflict. You are right, and it is deceptive. If they were acid free they wound not require buffering to change the pH to a safe level.
Like your skin Artwork and framing need to be kept at a neutral pH level. To neutralize the acids in paper pulp these mats have Calcium Carbonate added to maintain the pH balance at safe and natural levels.
The substance know as Lignin is then removed allowing the mats exposed beveled edge to maintain its original color or bright white core and not turn the dingy brown color of standard paper mats.
Rag Mats are mats made from the cotton plant and are usually of a higher quality. By nature they are designed to be acid free and Lignin free. The better quality rag mats are made from only the fluffy cotton material and not the branches and other material. They are safe for artwork and are designed to last many, many years.
Some Rag mats are refereed to as museum board or mat. Although that is usually in connection with a brand reference.
A note here, some Rag mat brands do use some of the Cellulose of the cotton plant. Not just the fuzzy part we think of when making cotton fabric. And yes again, this is deceiving. The mats are then Buffered to balance the pH.
Mats can be layered with contrasting or complement colors, or subtle and neutral. The can have the bevel or cut edge facing outward so that you can see the beveled cut edge of the mat. Or it can be reverse beveled or cut so you don't see the mats core, only the sharp edge of the cut. The average width of the mat used to be 2.5 inches as a standard. It is now considered 4 inches. The final choice should be what balances the artwork to the best effect.
Liners are the fabric covered wooden inner frames. They are traditionally used on Oil and Acrylic paintings on canvas. I was told by a friend that restored oil paintings, that liners were originally used because in the very early days of oil paints, they had a high content of organic material. This would interact with the Frames materials and gilding, causing a reaction and a greenish substance to form or grow. I imagine something like a mold or mildew. Anyway it became the norm to have a liner on canvas art. Esthetically it softens the transition for the hard surface of the frame into the softer surface and colors of the artwork.
Originally liners being covered with linen, only came in the beiges and whites that linen are made in. They are now available in every color of the rainbow, with leather and suede textures.
If you have read this far, you have already figured out I tend to do things a bit differently. I don’t believe in silly rules like you don’t do it that way, unless there is a really good reason. Just because its never been done that way, or you just don’t do that, doesn’t work for me. It is limited thinking. And the list of things that were not done that way until some one did it, is a very long list in human history.
So watch your toes, here I go again.
Using liners with paper art and glazing. Why would I even consider it? Well, because vs. mat boards, liners have depth, dimension, texture, colors and a richness that mats can’t come close to.
Depth: the profiles or shapes of lines create a depth between the arts surface and the glazing. I have found that mounting the glazing above the liner and between the frame accomplisher two things.
1.) It keeps the liner cleaner. Dust and environmental contaminates don’t get to it.
2.) It creates more space between the art and the glazing. Aside from the conservation need for the air space. The glass has a polarizing affect on the colors. The contrasts seem more vivid, the colors brighter.
Although probably not measurable, it also seems like some light that comes through the glass and reflects off the arts surface, hits the underside (inside) of the glass and is reflected back inwards. I have no way to prove this, but many times the image is just brighter with more depth or space.
Dimension: Liners have dimensional shape and form. They are three-dimensional, unlike mats that are flat pieces of hard board covered with a thin sheet of color, and sometimes fabric or texture. One-dimensional.
Texture and colors: Silks, linens, course, refined, leathers, suede’s. Dark, light, warm, cold, soft, feminine, masculine. I’m sure you are seeing the pattern develop here. Variety. They provide a richness that mats being one-dimensional just can’t match. If you are getting the feeling I like them, you are very right. But don’t take my word for it, come in and see for yourself. Does it mean, use a liner over a mat every time, no. But I can assure you that when you see the difference, you will ask the question, why can’t you do that.
Just a point here about cost and size. Liners are usually smaller in width than mat borders, so the frame is smaller. Everything in framing is measured by the united inch, height + width. Then a conversion chart is used to determine the length of molding required. So less molding, and less glazing is used. So when you compare the cost of the liners against the cost of a double or triple mats it is usually very close. Mats are really good for making a piece larger by using a wide mat border three to six inches. This gives it more presence on the wall, and sometimes bigger is better.
This is short and simple. Spacers are channels or box shaped plastic. They function like mats and liners to provide an airspace, and to help insure the artwork won’t stick to the glazing. The better products are inert and do not off gas, or release chemical as they age.
They come in two styles one uses an adhesive to stick to the edge of the glass. And with time and the effects of gravity, they can and often fail, drooping down into the visible area of the artwork. The second type uses a channel built into the spacer to mechanically wrap around the edge of the glazing. When it is installed into the frame it cannot move, fall, or change position. It is more work and expense to use these. The glass should be stoned to remove shards and burrs from the edge so it can be slipped over the edge.
We do this anyway; it keeps the shards of glass from falling into the package or artwork. So it takes a bit longer and costs a bit more. There is the best way to do something, and then there are the other ways.