Bleeding color usually is a matter of moisture in the frame. Some fabrics also have the possibility of offgassing, which could be a problem in the closed-up atmosphere of the frame. Have you ever walked into an older, smaller, less-well-ventilated fabric store and reacted with watery eyes or stuffy nose, or noticed an acrid smell? The dyes, sizings, and other additives to fabrics are the probable cause.
Tradeoffs, yes. For example, a moderate level of preservation could be achieved by spacing the art/document/object away from the fabric by using an undersized mountboard or some kind of inert, stable spacer. In most cases that would take care of a bleeding color problem.
The offgassing problem, when it exists -- and most of us can't tell when it does -- is another matter. The damage would be done before anyone knows there is a problem. So, prevention is the only safe answer.
I am familiar with the Moorman boards off-gassing hydrosulfide, but it was my understanding that it came from their commercial bonding agent and the fact that the "fabric" was heavily sized, but I am curious as to your experience with regular fabrics off-gassing.
Could you tell us which ones you have found to off-gas? What test can we use, short of a atomic spectromitor in a baric chamber? [I'd sure like to save a little money.]
Darker colors have more problems than lighter ones. Heavily dyed fabrics are more likely to need
mordants to set the dyes and their color can rub
off on items that are in contact with them. Metals and photos are the most vulnerable. Undyed
fabrics that have had finishing materials laundered out of them are the best choice.
Bainbridge makes several fabric matboards that meets FACTS PMMB2000 for preservation framing. The linen is made in Belgium, the lignin is removed and there is no sizing, only safe dyes and the attaching adhesive is also preservation grade. Their AlphaLinen line plus the Alphadenim is preservation grade and they have Artcare (zeolites) in them. I believe Scott at Raphael's fabric has done some testing on his fabrics as well as Frank at Frank's Fabric. Ask which of them meets FACTS PMMB2000 or are preservation grade.
A linen flag is not as reactive as an item that
contains metal and keep it with linen is not
likely to pose too much of a problem. The support
linen should be thoroughly laundered win washing
soda and then rinsed through several cycles with
clear water. There is a very slight amount of
residual ligin in linen, but so slight that it
should not pose a problem, especially for a
Edie, When Hugh says "clear" water, he doesn't mean Perrier or Evian....
You need to get a gallon jug of "distilled" water. and remember to first wash your hands with dish washing soap... or wear gloves.
Only the dish washing soap will remove the oils completely from you hands.... oils that contain amino acids like sulfuric and hydrocloric.
You could cut a slightly undersized rag mat and turn the wash raw linen over and glue down... but leave about 1/4" unglued on the back for easy stitching. Stitch the flag down to the very edge of the undersized covered mat. Then glue down the matboard to the back mat with Frank's Fabric Adhesive... wont take more than several spots, or run a perimiter line about 1" in from edge which will allow for a future spatula to get in and under if need be. Weight overnight.
Washing soda raises the pH of the wash water quite high, so acts as a detergent booster. It can also act as a mordant for some kinds of dyes, attaching them firmly to the fabric. It should only be used with cellulose fabrics as the high pH would damage silk or wool or nylon. Probably wouldn't do polyester any harm.
Although I use deionized water for cleaning historic textiles, most tap water is fine for show fabrics, unless you have a real problem with iron. Even then, Calgon should do the trick.