Gamblin PVA Size diluted with distilled water is a contemporary size for fabric support. Conservation scientists recommend painters use neutral pH PVA size on linen and canvas instead of rabbit skin glue. PVA (Poly Vinyl Acetate) seals the fabric but does not re-absorb atmospheric moisture, preventing the size layer from swelling and shrinking. It has a neutral pH and does not yellow, plus it retains its flexibility, does not emit harmful volatiles, and protects fabric from the ground. PVA does not tighten the fabric like rabbit skin glue, so stretch fabric tightly.