<p>"Stock" refers to the sticker material that we print on. Different stocks are available depending on which product you are ordering. Unless you specify, white vinyl with lamination is the default material that we use in manufacturing the stickers. <p>Available Standard Stocks: <p>Clear Polypropylene - This is a 2-mil clear film stock. Very similar to vinyl but a bit thinner and without lamination. This clear stock is normally used on the standard spot color prints. We normally provide a free white ink backer on this type of standard stock print. Not recommended for outdoor use. <p>White Vinyl with lamination is a 4-mil thick stock with a 1 mil clear polypropylene lamination for the highest gloss and added durability against scuffing and general wear and tear. This material comes with a heavy-duty liner ranging in thickness from 78# to 100#. Clear Vinyl is a clear stock with a medium level of durability. Our standard clear spot color bumper stickers are printed on this stock with a 1-mil lamination. Our standard clear CMYK stickers are printed on this stock with a UV varnish. The stock appears almost crystal clear. We normally provide a white ink backer at no charge on this type of standard product. Adhesive is available on either the face side or back side of the label. White Vinyl with UV varnish - This is the stock that the standard white vinyl CMYK stickers are printed on. This stock has a medium level of durability. This stock works well as labeling and as a promo product too. The CMYK stickers are only available on white stock. If you are interested in the more premium and more durable sticker product just ask about our custom screenprinted sticker products.