A typical Russian canvas construction method?

[OlymposPartizanos]

Placing a verticle haircloth in the middle of the chest. Such a method went through most of books from Soviet period that I collected, all the way from 1930s to 1980s. I've nearly never seen it mentioned in other languages (excepet a Chinese one, which I know they did have some Russian influences). Probably it would create a more round shape on chest?








Exapmles from 1930s, 40s, 50s and 80s.