Acid free tissue must be used when packing these items, to prevent acid or any poisons being released onto these goods while on the shelf or in transit. A ream of 500 sheets of white acid free tissue paper, dimensions 450mm x 700mm. This is a commercial acid free tissue paper with a weight/strength of 18gsm. Acid free tissue paper is great for presentation, and also required when packaging items that are designed for food use (eg. crockery, cutlery etc).