Anne was asking about double weave hems, so I'll take the opportunity to show you how to draft them, no matter how many shafts you are using.
The weave structure for a plain double weave on a straight threading for 4 shafts would look like this—just plug it into the lift plan:
Using a single shuttle with this draft, you would weave double plain weave, tubular fashion, alternating one pick of bottom layer, one pick of top layer. For any multiple of 4 shafts, just repeat this structure horizontally as needed for your particular liftplan. Following are the 4 shaft, 8 shaft, and 16 shaft versions:
And here is the complete draft for 16 shafts, with four repeats of liftplan.
Photos of completed hems here.
By the way, if you are a fan of Network Drafting (see book in sidebar), this liftplan also weaves double weave on any threading based on a network developed from a 4-end initial. Here's an example:
Weave twice the length you need for a hem, at beginning and end of the piece. When the cloth is cut from the loom, just tuck the raw edges into the double weave tube and whip closed by hand.
For really good references for double weave, check out Jennifer Moore's website—her books and DVD's are excellent.