• Litmus is a water-soluble mixture of different dyes extracted from lichen. Dyeing filter paper either red or blue with this ink creates one of the oldest forms of testing alkalinity and acidity. Blue litmus paper turns red under acidic conditions. Sold in boxes of 100 strips of paper.
• Estimate of alkaline pH levels
• Blue Litmus

Litmus is a water-soluble mixture of different dyes extracted from lichen. Dyeing filter paper either red or blue with this ink creates one of the oldest forms of testing alkalinity and acidity. Blue litmus paper turns red under acidic conditions. Sold in boxes of 100 strips of paper.