The LAB STAR Blue Litmus Test Paper is a reliable and straightforward solution for qualitative acid-base testing. Each pack contains 100 individual strips, making it a convenient and long-lasting supply for regular use. The working principle is simple — when the blue strip is exposed to an acidic sample, it changes colour from blue to red or reddish-pink, allowing for quick and easy acid detection without the need for any additional equipment. To use, simply moisten the indicator portion or briefly dip it into the sample and observe the resulting colour change. The strips are supplied in a protective plastic dispenser that keeps them organised and shields them from environmental moisture during storage. Suitable for a wide range of applications including chemistry laboratories, school and college practicals, science demonstrations, water testing, industrial process checks, and general research work. These export-quality strips are an essential tool for students, educators, and laboratory professionals alike.