MC Robin Double Knit 100% acrylic; 328 yards/300 m per 100g skein; color: yellow; 1 skein
CC Patons Diploma Gold DK 55% wool, 25% acrylic, 20% nylon; 131 yd/120m per 50g skein color: black; 2 skeins

From the designer:

This scarf is worked in double knitting. This is a technique which allows you to form two layers of fabric at once. It can be used in different ways, but in this case, it is used to make a reversible scarf with a stockinette surface on each side. One side will be predominantly yellow, and the other side will be predominantly black.

When working a two-color pattern in double knitting, it is helpful to think of one side of the fabric as the ‘Right Side’, even though both sides of the piece will look equally good. Each stitch in the color pattern is really made up of 2 stitches: one stitch on the ‘Right Side’, in the pattern color, and one stitch on the ‘Wrong Side’, in the other color. The pattern will explain how to do this, in more detail.

I have included a chart, but it is worth knowing the logic behind the pattern, because you can write your own, or even work without a chart. In essence, it is a form of decomposing check; how it goes through this decomposition is up to you. You start from nothing, adding first one odd square, then another, then another, until you’ve achieved a checkered pattern. You can decide whether you want to add or lose squares as you go along, depending on how you feel.

It is easy to end up with a loose fabric when working in double knitting; be sure to knit with a firm tension/gauge.