Exceptions and special cases

Canvas & needleart

• Needle Art is mounted to Acid-free foam core, rag-lined acid-free foam core, or cotton rag foam board using stainless steel dress pins (no rust), lacing or couching whichever is most appropriate.  No tapes, glues or adhesives are used (these may stain or rot the fibers).  Glass should not touch needle art as moisture or condensation could collect inside the package, causing rot or mildew in the needle art fibers.  If no mat is used to separate the Needle Art from the frame (wood) the frame should be lined with a conservation quality barrier tape that has an aluminum or copper barrier to prevent bleed-through of acidic materials (Archival Frame Sealing Tape is one such item). In this case a spacer should also be used between the art and glass.
• Oils or acrylics on bars or boards: The same barrier tape may be used to line a  wood frame before inserting the artwork.  The latest thinking on canvases is to back the frame package with Archival Foam Board. This will prevent puncture and environmental damage.  If the piece is valuable or of high sentimental value conservators are now recommending some type of conservation glazing with a spacer between the art and glass, a foam rabbit tape can also be used to protect the face of the painting from pressure.