"Verrocchio" envelopes are made from Duralong PaperPhoto quality paper, glued on two sides with an acid-free adhesive and open on the short side with non - adhesive flap. The envelopes are internally padded with shaped felt, compact and flexible, covered with japanese paper of 18 gr/mq. They are made with a double expandable side fold to facilitate the adaptation of the various thicknesess of the artworks. External envelope

TECHNICAL SPECIFICATIONS
• 100% Alfa cellulose
• Buffered (calcium carbonate reserve)
• pH 8,5 - 9,0

Internal padding
TECHNICAL SPECIFICATIONS

• Felt: 65% Polyestere + 35% Cotton
• Japanese paper: 30% Japan kozo + 70% Manila
• Unbuffered
• pH 6,5
• smooth non-abrasive surface
• Air permeability: not less than 40 liters per dm² / min