American Crafts Scrapbook Utility Pen, PH Tester Pen
The American Crafts pH Tester Pen may play a supporting role to other pens and markers, but it's equally important. The pen features a specially formulated solution that allows you to test the level of acidity in paper products. Draw a short line in an inconspicuous part of the paper. Blue or lavender ink indicates a desirable acidity level; yellow or colorless ink indicates and undesirable level. pH Tester Pens are non-toxic and 100-percent archival.