Lineco pH Testing Pen is a quick and easy way to determine if paper or paperboard is acidic or safe for precious collections. With a simple swipe of the pen, one can distinguish the difference between safe (neutral or alkaline) paper and board and acidic materials.
Simply draw a line on the material to be tested. The chlorophenol red indicator solution in the pen will turn purple on any paper with a pH of 6.8 and above. A clear or yellow color indicates the material is probably unsuitable for conservation purposes. Please note that unreliable results may occur on colored or coated papers.