Russian women used to treat fabric very carefully long time ago. They tried to use each patch of fabric after clothes sewing. Probably this was the reason of appearance of such rug.
For large rug you will need:
Base fabric (size of future rug),
Different scraps 2 x 2” (5 x 5 cm).
Mark control lines on the base fabric.
Bend squares twice and start to sew from the center. Play with color!
For small circles use trapeze patches.
The real master of small circles is Alla Snegovskaya from Moscow. Here are some of her works.