Envelope of recycled paper - with synthetic resin lacquer layer film between gum layer and paper on rear flap

摘要

Envelopes made of recycled paper have heavy metal impurities which have detrimental effect on the gum and cause a premature ageing of the gum on the closure flaps of the recycled paper. It is therefore suggested to interpose a layer of synthetic resin lacquer which prevents a direct contact of gum and recyled paper. The gum is also covered by a tear-off film of silicone paper. ADVANTAGE - This eliminates the problems with envelopes made of recycled paper.