1. Base material. The best kind of canvas is to get is 100% cotton canvas. Be aware that there are different versions of canvas that have a lower percentage of cotton, along with some other, usually manmade fabric. To get the nice, breathable tarps you expect when you buy canvas tarps, you will want 100% cotton. This will ensure that moisture does not condense under the tarp.

2. Density. The denser canvas are, the stronger they are and the more durable the tarp will be in the long run. 12 ounces per square yard is a good density for heavy duty tarps such as canvas tarps. This means that the tarps will not tear easily or wear through quickly. Poly tarps have a lower density because of their lighter weight material, but canvas tarpaulins are really made to last.

3. Sewing specifications. The way canvas tarpaulins are sewn makes a big difference in their quality. Look for 1 inch double stitched seams. This will ensure that the seams will not ravel out and leave the tarpaulin in pieces. For hems, those of 1.5 inches are preferable, with the edges folded towards the inside and then stitched. This will keep the edges of the tarpaulins from fraying.

4. Grommets. You will want to make sure your canvas tarpaulins have good brass grommets to make them long-lasting and sturdy. It is important that the grommets not be too far apart to be useful. A good distance is every 24 inches. This will allow you to tie the tarp down securely if you need to use it that way.

5. Water resistance. You are not likely to find canvas tarpaulins that are 100% water proof. However, you can find this sort of tarpaulins manufactured by using a wax process to render them water resistant. This makes the tarp more versatile in the ways you can use them. For example, if you were to spill paint on a thin canvas tarp that was not water resistant, it would probably bleed through to the floor. However, with heavy duty water resistant canvas tarpaulins, you will not have that problem.

Look carefully at the details of any types of canvas tarpaulins you think about buying. Make sure you have found heavy duty tarps that will suit your particular needs. If you shop carefully, you will be able to find one that will last a very long time.