This cushion cover with plain but clever design comes without side seams.
it got a common size, you can get the inner cushion for example from Ikea. If you want I can send it with inner cushion, too. But then the international shipping will get more expensive.
The cover is knitted from 100% english lambswool.
with zip on the back.

Washing with wool cycle
50 x 50 cm 
20" x 20"