Glass is not just glass. In the world of framing, there are big differences that glass has on your custom picture frame (and admittingly on your final price). It is good knowing what kinda choice you are making, when you are asked, what about glass?
Glass is a non-crystalline, solid material. The most commonly know of which is based on the chemical compound silica or silicon dioxide. Sand is mostly made of silica, and thus historically much of glass was made from sand; however, modern day glass is a careful combination of multiple materials, including, gypsum, dolomite, soda-ash and limestone.
Standard Picture Glass
This is the most common form of glass found in picture frames. This “plain” glass has a natural green tint to it due to its iron content, and is usually 2mm or 3mm thick. Standard picture glass is ultimately the least expensive option for protecting your art from dust and dirty fingers. The major negative with this option is that you will see a strong reflection in the glass. If the frame is located somewhere with lots of natural sun light or overhead lights, you will not be able to see the image properly, and over time, the image will start to discolor due to a lack of UV protection.
Also know as Museums Glass, there is a lot going on here:
- Protects against the damaging effects of ultraviolet rays
- Reduces reflections to less than 1% – making the glass virtually invisible
- Has a coating that resists dust
- Low iron percentage, giving glass zero color shift
Museums glass is also typically 2mm or 3mm thick, and is the only real option for truly protecting any art that has real value to it. With the UV protection, it helps to prevent discoloration over time due to sunlight, and of course, with the anti-reflective properties, you get to fully appreciate your image. But as one can image with these increasing benefits, one has significantly increasing, usually 2-3times more than normal glass costs.
Also know as “Plexi” or “Acrylic” glass, this light weight and non-breakable glass could also be considered for framing large works (thus making the overall frame lighter), particularly those that might be transported often between shows (less likelihood of breaking). Other than these two positives, plastic glass scratches extremely easily, which can only be resolved by replacing the plastic. In addition, it retains a high static charge, which makes dust stick to the surface, and potentially un-usable for artworks made of pastels or charcoals. There is the possibility to buy acrylic glass that is enhanced with an UV filter and has anti-static coating, but this increases the price tremendously. Please do not believe that because it is plastic, it is cheaper than normal glass—it isn’t. Acrylic glass often has to be ordered to size, increasing its costs, and due to the previously described negatives, might not be worth it.
Of course we can always use some recycled glass for your upcycled picture frame! If you have your own piece, we can use it, so bring it with you. Since upcycling is our business here in Berlin, we also have some pieces of old glass.
Old glass is unique, because the process for making glass for contemporary wooden picture frames was different then today. Therefore, old glass tends to not be even, having some parts thicker than other. Frames for paintings don’t need any glass, but for those vintage frames, old glass has a pretty unique look to it.