Glass, museum glass, and acrylic
Jerry Polizzi ·
The shop glazes with clear glass, non-glare, acrylic, and UV-blocking museum glass. The sheet is there to keep dirt and a share of the light off the work, and to come off again without taking the surface with it.
What the light does
Paper fades from light, not only from the ultraviolet part of it. Direct sun is the worst of it. UV-filtering glazing blocks most of that ultraviolet and slows the fading. Bright visible light still does damage. An interior wall is the better place, even with museum glass. Hanging and storage are in caring for works on paper.
Clear, non-glare, and museum glass
- Clear glass shows the color truly and reflects whatever is opposite the frame.
- Non-glare glass is etched. It cuts reflection and can soften a dark image, especially when the art sits well behind the glass.
- Museum glass, as the shop uses the term, is the UV-filtering sheet that also cuts reflection, without the etched haze of ordinary non-glare.
Non-glare and ultraviolet filtering are different things. Etched glass does not, by itself, block UV. If you need both, ask for both.
When the sheet should be acrylic
Acrylic is lighter than glass, and it is the safer sheet over a sofa, in a hallway, or on a poster large enough that broken glass would be dangerous. It scratches more easily. It can also hold a static charge, and that charge can lift pastel, charcoal, and any pigment that is only sitting on the paper. Printed ink on a poster is usually fine. A powdery drawing should be discussed before acrylic goes on it.
Glass against the ink
If the sheet touches the glazing, moisture can stick them together. A mat or a spacer keeps a gap. A brown mat board against the paper is its own problem, covered in how to frame a vintage poster. Replacing the glass in an old frame is a good moment to have the sheet rehinged, rather than prying the frame apart at home.
These notes are the advice we give across the counter. They are not an appraisal and not a conservation report.
Questions
Is museum glass worth asking for?
On a work you want to keep, and on a wall that gets any daylight, UV-filtering glazing is the part of the frame that does the most. On a diploma in a dark hall, clear glass may be enough.
Does non-glare glass block ultraviolet light?
Not by itself. Non-glare describes the reflection. Ultraviolet filtering is a separate coating or a different sheet. Ask for both if you need both.
Can the glass in an old frame be replaced?
Often yes. If the old glass is against the print, or the mat is brown and brittle, bring the whole frame in. Changing the glass is a good time to hinge the sheet properly.