This box not only has a lid, but a seamless construction, shaping and an integrated hinge thanks to the marled stitches used. It is loosely based on the masu box, a traditional origami pattern.
For practicing techniques, this is an ideal small piece — it has cast-on, bind-off, increases, decreases, color-changing, simple two-pattern double-knitting and marled knits and purls. However, it’s also designed to be sturdy and stand up on its own, so the fabric is tough and unyielding, for the most part. This is not something you want to hear about most knitting projects, but for a box it’s not a bad thing.
This pattern is currently available only in the 2018 revision of Extreme Double-knitting.