This method is just like the knit bind-off, except
you purl instead of knit. You use it to bind off
purl stitches.
1 Purl until you have 2 stitches total on the
right needle; then insert the left needle
into the front of the first stitch purled onto
the right needle.
2 Pull the first stitch over the second purled
stitch and off the right needle.
You have bound off 1 stitch purlwise, and
you have 1 stitch on the right needle.
Basic Techniques
chapter 2
3 Repeat steps 1 and 2 until you have bound off the desired number of
stitches.
How to Bind Off Purlwise
FAQ
What do I do when I have bound off all stitches
and have only 1 left on the right needle?
When you are binding off all the stitches that remain
and you have only 1 stitch remaining on the right
needle, cut your working yarn, leaving a tail at least
6 inches long. Thread this tail through the last stitch
and pull tight.