When selecting the right size and thickness for a heavy duty PVC tarpaulin, consider the specific application and environment where it will be used. For covering large items or areas, measure dimensions accurately to ensure full coverage. Thickness is indicated by the tarp's weight (oz/yd²) or mils; heavier, thicker tarps offer superior durability and are more resistant to punctures and tears. Think about the conditions it will face - if the tarp is exposed to high winds or heavy loads, opt for a thicker option to ensure longevity and performance.