Stonehenge Oil Pad contains 100% virgin cotton fiber paper specifically created for oil painting. This receptive new surface for all oil paints has internal and external synthetic sizing and is mould-made, acid-free and archival. Paints will not bleed through to the other side and does not require any prep or gesso. The paper will remain flat and maintain an even textured surface allowing free flowing brush strokes. The pads feature 12 sheets of 140 lb. (320gsm) paper.