Uchida Neutral 7 Acid Identifier Pen

Quickly identify the acid content of paper and textile products using the Neutral 7 Acid Identifier pen. When a high acid content is presen t the pen makes a yellow mark. Strong alkaline content is indicated b y a blue mark. Lime green to dark green marks indicate a surface whic h is acid neutral and safe for scrapbooking. Each individual pen is held in a slim clear plastic case for peggability.