The project can be worked as stranded knitting or Double Knit. Stranded knitting uses less yarn while Double Knitting produces a reversible result or a more stretchy pillowcase.

If you choose Double Knit, as the pattern is quite large, you should have some experience in Double Knitting before you start working on this pattern. I suggest to practise Double knitting on one of my free, smaler DK Potholders first.

Reversible Pillowcase
The pillowcase is reversible like this: On the front you have the white sheep, on the back singly knit seed stitch, the pillow is closed by a flap. if you turn the pillowcase inside out, you have blue sheep (or brown or whatever your second color) on the front and still the single seed stitch on the back.

Inspired by the Playful Lambs illustration from “Baby World Stories, Rhymes and Pictures for Little Folks”, 1884, in public domain.