Colorwork in Double Knitting: Casting On

This is one way of casting on for two-color double knitting.

Make a slip knot in each color and put them both on one knitting needle. Then pick up the first yarn (white in my photo) and make a backwards loop.

Drop the first yarn and bring the second one (blue) towards you, and cast on another backwards loop. As you cast on each loop, be sure to bring it forwards, so the two yarns to cross and twist together. If they don't cross, you will end up with an open tube on one end.

An open tube is fine, if that's what you want.

There are certainly other ways to cast on for two-color double knitting, but this one is pretty easy to describe.

If I get brave, later I will try to show how to use the provisional cast-on for starting double knitting. I would not say this is easy: in fact, it's very "fiddly", but I like the results enough that that is how I usually cast on for double knitting.