Place felt ball is a way of knitting with felt balls to embellish your knitting. First you pre-string your felt bobbles. Then place them in your knitting, and knit around them.
Sometimes this embellishment is written into a pattern using the phrase place felt ball. Sometimes it is written into a pattern as k1-bubble.
How to place felt ball
Pull up one felt ball until it is as close to previous stitch as possible, then use yarn immediately after felt ball to knit stitches.