Another tidbit about framing and humidity. Wood, paper, and cotton stuffing (cellulose products) have a strong control on humidity, even in well-sealed containers. I recently did some research on this topic (for natural history specimens, not lace). Specimen storage cases have good, but not perfect seals. Humidity changes outside the case gradually change the humidity inside the case. However, if there are wood drawers or cotton-stuffed animal specimens, the humidity inside the case remains constant. This means the cellulose is absorbing extra humidity and releasing it back into the air inside the case.
Therefore, the matt board, backing, lining on the back of the frame, even the frame itself (if it's wood) and the lace (if it's cotton or linen) will control the humidity inside a "sealed" picture. I can guarantee that a picture with a piece of paper taped all around the back is not as good a seal as our specimen cases, so there's not going to be a problem with the lace "breathing". The function of the tape and paper is to keep dust out, not seal the air out. "Sealing" the picture will not significantly affect the humidity that the lace experiences, and the mounting materials will cut down considerably on the amount of humidity fluctuation. I mean the day-to-day and week-to-week fluctuations, the seasonal difference between humid summer weather and ultra-dry heated-house winter conditions (for those of us who have these conditions). The humidity inside the picture or case will rise or drop with the long-term seasonal changes, but it will be slowly. There is some evidence that protein materials (feathers, leather, hair, silk, wool) also absorb and release humidity, but I haven't done the carefully-controlled experiment to demonstrate this. Robin P. Pittsburgh, Pennsylvania, USA http://www.pittsburghlace.8m.com/ - To unsubscribe send email to [EMAIL PROTECTED] containing the line: unsubscribe lace [EMAIL PROTECTED] For help, write to [EMAIL PROTECTED]
