For picture framing glass and acrylic are the two most popular choices. They are both often chosen for this same task yet glass and acrylic have different properties with pros and cons to them both. Depending on the situation one may be preferred over the other.
Plastic experts, The Plastic People, offer guidance about the suitability of acrylic for framing requirements.
Undoubtedly the biggest benefits of acrylic to picture framers are its strength and durability. Compared to glass acrylic is incredibly lightweight yet much, much stronger. For large pieces of artwork, where glass can be dangerous to handle (threatening to flex and snap) as well as dangerously heavy (causing frames to bow), acrylic is an exceptional choice.
The next biggest reason is likely financial. For artworks which are likely to be moved around a lot and especially for pieces that will be shipped, acrylic is a sensible financial decision given the significant loss of value any damage will create. Couriers transporting artwork which becomes damaged typically only the value of the items used to create the work; (ie, the paint, the paper and the glass) rather than the full market value of the artwork. Acrylic helps sidestep this discrepancy and potential disaster.
However, despite being stronger and more durable, acrylic is also more fragile than glass in that it is easily scratched. In the first instance, acrylic should be supplied with a plastic film on both its sides so when this is peeled away, the acrylic is completely perfect compared to glass which is usually dirty and dusty when bought, requiring meticulous cleaning. To prevent scratching, acrylic should only ever be cleaned with a soft cotton cloth and warm soapy water or a specialist acrylic cleaner like Vuplex (as opposed to a glass cleaning product). If acrylic does scratch, all is not lost – fine scratches can be buffed out by hand or by using a scratch removing product like Xerapol.
For picture framers clarity is key. At 3mm thick, acrylic and glass are indistinguishable in frames. However, anyone who has ever handled a glazed piece and loaded it into a frame to discover dust trapped on the glazing will understand the frustration of trying to remove static build up (the cause of clinging dust and lint!) which happens with both glass and acrylic
There are ways to eliminate it. With glass, we understand that leaving glass to dry on its own rather than wiping it dry helps (though we are not glass experts, only plastic!) Another option as is brushing the glass once with an anti-static brush (before loading the glass into the frame.) It’s much the same with acrylic – brush the acrylic sheet with an anti-static brush after peeling the protective film off..
When it comes to cutting, glass beats acrylic as it is easier to cut. However, there is always an option to buy acrylic cut ready to the size you require. Because it is super strong, it can be delivered out to you safely.
Last but not least, acrylic can be more expensive than glass. Acrylic prices can fluctuate because it is a petroleum based product, susceptible to oil price spikes.
So in summary, when it comes to durability, cleanliness and weight acrylic wins every time. On price (and cutting, if you are doing it yourself) glass often wins.