Wouldn't you prefer to spend hours and hours printing your own tablecloth clips instead of buying them for 10¢ each? LOL I designed and made these after reading reviews of the commercially available clips and didn't like how they were always downrated due to unexpected breakage or overnight cracking or didn't fit their table thickness. So voila. First, these are stackable. If you need to carry four or eight or a whole bunch to a picnic, they're lightweight and compact. Second, they're flexible. I printed mine in polycarbonate. The smallest can fit thicknesses of 3/8" to 2 1/2". The largest can fit 3/4" to 3". So for a common wood picnic table of 1 1/2" thickness, using all four is okay. The different size is unnoticeable. Lastly, the corners are thickened for increase stiffness, i.e., better performance.Print one or print all four, but best to print in a material that's stiff and flexible. Note that neither ABS nor polycarbonate is UV resistant, meaning they'll degrade and get brittle after long exposure to the sun.