Mont Marte Leafing Size is a non-toxic, water-based gilding adhesive. It stays open where extended tack time is required, dries to a translucent finish and cleans up in water. It can be used straight from the bottle with no dilution on porous and non-porous surfaces including wood, plaster, glass, metal, leather and canvas. Proper tack develops in about 25 minutes at normal humidity and remains open for up to 24 hours.