If choosing a colored mat, make sure the matboard is colorfast. By colorfast I mean that the color will not “run” when the paper is wet. Noncolorfast matboard can stain a note if it gets wet.
Testing for colorfastness is straightforward. Ask your framer for a small scrap of the matboard you plan to use. Soak the matboard in warm soapy water and, when fully saturated, press it against a white paper towel. If no color transfers to the paper towel, then the matboard is colorfast. If there is a color transfer, then the matboard is not colorfast and should be avoided.
In addition to a front window mat you should also have a back matboard. The back matboard should also be good-quality, acid- and lignin-free and colorfast. The front and back mats should be taped together using a gummed linen tape. Acidic materials such as masking tape should be avoided.
How you mount the notes is important. The method you choose should be completely reversible and cause no long-term damage.
“Dry mounting” is not easily reversed without damaging the paper. Dry mounting is a technique that is best reserved for low-value works such as posters.
Works of art on paper are normally mounted by hinging them along the top of the paper to the back matboard using small Japanese paper hinges. The hinges are adhered to the work and the matboard using either wheat or rice starch paste. These pastes are strong, stable and completely reversible. A number of self-adhesive mounting tapes are available but should be avoided. When mounting a paper note, I prefer not to use hinges or any adhesive at all. Instead, I place the note in a Mylar pocket which is adhered to the backside of the window mat using 3Mtm 415 archival-quality self-adhesive tape. The note sits safely in the pocket and can be easily removed at any time.
For detailed instructions, readers should check out the Northeast Document Conservation Center’s online pamphlet, “How to Do Your Own Matting and Hinging.”