I used 12 different acrylic yarns from my stash to make this project. It's mainly Wibra Saskia and Zeeman Royaal, in different bright colors. Some other brands too, but I lost the wrapping paper so I don't recall the name. Oops... :)
Anyway, the pillow has a diameter of about 30cm and is about 15cm in thickness. I made a pillow insert of cotton muslin, which I filled with polyester stuffing.
And here are some more pictures: