These round stickers come in two sizes - 1 1/2", or 3" - and you can buy them on sheets with 20 of the small stickers or 6 of the large ones.
So you've really got no excuse if there are small, circular, knotwork free voids in your life. I've got you covered for anything up to three inches across.
Anything larger, I think, qualifies as a medium sized, circular, knotwork free void; scientists are currently researching a solution for those.
It's a knotty problem.
The art on these pages is copyrighted, at dates between 1997 and the present, by Bradley W. Schenck. This web site is entirely safe when used as directed. The large print giveth, and the small print taketh away. If you're reading this you are way, way too close and - possibly - you have too much time on your hands.