A Glass Spacer is a tubular or rectangular plastic strip that fits discreetly under the lip of a picture frame, positioned between the glazing (glass or acrylic) and the backing board. Its purpose is to create a three-dimensional space inside the frame so that artwork, photographs, textiles, or dimensional objects do not come into direct contact with the glazing. This separation helps preserve the artwork and maintain a professional presentation.

Function in Framing

Protection: Prevents condensation transfer, mold, or adhesion between the artwork and glazing.
Visual depth: Creates a shadowed recess that adds dimension, often enhancing presentation of photos, prints, or objects.
Support for thicker pieces: Allows the framing of textiles, medals, coins, or other dimensional art within a standard frame.

Materials and Types

Plastic Spacers: Clear or neutral-colored plastic (often acrylic or styrene) that is lightweight, durable, and inert.
Foam Core Spacers: Cut from acid-free foam core board; a more economical but less durable option.
Custom Depths: Available in multiple thicknesses to match the depth needed for the artwork.

Installation

Spacers are cut to the length of each frame rail and snapped or tucked under the lip of the frame.
They remain hidden once the frame is assembled.
No adhesives touch the artwork or glazing directly, maintaining reversibility in conservation framing.

Conservation Considerations

Archival quality: Choose acid-free, inert materials to avoid long-term chemical interaction with artwork.
Air circulation: Spacers should provide sufficient clearance to prevent microclimates where condensation can form.
Compatibility: Avoid non-archival foam or plastics that may off-gas or discolor over time.

Best Practices

Always use spacers when artwork would otherwise touch the glazing, especially with photographs, pastels, or delicate media.
Select spacer depth according to the thickness of the art package.
Pair with UV-protective glazing for maximum preservation.
For shadow box or object framing, combine spacers with deep frame profiles for added dimensionality.

FAQs

Are glass spacers visible once installed?: No. They are hidden under the rabbet lip of the frame, ensuring a clean presentation.
Can I use foam core instead of plastic spacers?: Yes, though foam core spacers may be less durable and prone to compression compared to rigid plastic spacers.
Do glass spacers work with acrylic glazing?: Yes. The term "glass spacer" is traditional, but they are equally effective with acrylic glazing.

Glass Spacer