A provisional cast-on keeps cast-on stitches "live" so that they can be knit later. It's a very useful technique when you're not sure what kind of edging you'll want or how long to make something. With a provisional cast-on, you can make these decisions at the end of a project, allowing you to respond to the actual garment. I made this tutorial to go with my 70's Ski Hat Project Journal, the provisional cast-on is used to make a cashmere lining for the hat.

There are a few ways to make a provisional cast-on. This is my favorite...

• With some smooth waste yarn and a crochet hook, chain a few more stitches than you will be casting on. Cut the tail and pull it through the last stitch.
  

Examining the chain, the front side is made up of V's.

The back of the chain has bumps in it. 

• Insert a knitting needle into each bump on the back of the chain, and pick up however many stitches you're casting on.

Then just knit!

• When you're ready to use the cast on stitches, thread a knitting needle through the right side of each stitch. It's like weaving - over a strand, under a strand...
  

•  Then remove the crocheted chain by untying the end and gently unraveling the whole chain.

You're ready to knit in the other direction!