Mont Marte Leafing Size is a non toxic, water based gilding adhesive. The adhesive stays open where extended tack time is required, it 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 will develop in 25mins at normal humidity and it will stay open for 24hrs.