Thank you for your interest in Danco products. The Danco 00 Flat Washers, model 35266, are made of Buna-Nitrile rubber.
Thank you for contacting Danco! It is recommended that you use the 00 Flat Washer on "quick opening" faucets. The 00 Flat Washer (1/2 in. OD), also comes in packages of one, Danco model # 35062B.
You could use this product for that but the designed product it made to replace leaking faucet washers. These would fit a small nail and provide more surface area to keep your tarp from tearing so easy.