This pen will quickly identify the acid content in rubber stampable materials and memory book albums. It can also be use to determine the acid content of stickers, textile products, doilies, stationery etc. Acid-Free/Non-Toxic, Photo Safe. Fine point tip.
How it works...
Water Based blue coloured ink is chemically active: Stays a bright blue when paper is alkali, a bright yellow orange tells you a high acid level is present. An ideal color is anywhere close to a greenish tint. The scale is conveniently printed directly on marker.