What does k1b mean and how can you do it?
k1b means knit one back, and how you do it is you insert your needle into the back of the loop, wrap your yarn around like you do when you knit regularly, pull through.
Amy has a video on it too.
Hmmm, this could prove to be a bit confusing because K1B, can also mean to knit into the stitch below. There is a video on this page: