There are three main reasons to block your knitting. One is to improve the overall appearance of the knitted item.

 

Blocking separate pieces of stockinette stitch fabrics allows the seam to be straightened out and those edge stitches become more visible for seamimg. Blocking the whole garment allows for seams to become more defined and supple.

 

The last reason to block is to correct gauge errors or increase length or width of a knitted piece.

 

It is said that there are as many ways to block your knitting as there are knitters. Each fiber has conditions regarding care so no one blocking method is going to work for every situation.

 

Questions to ask before a blocking technique is chosen include can the fiber be wet, can it withstand heat, and can it withstand pressure. Paper or silk yarns may not be candidates for soaking or even water. Some pieces can be sent to the dry cleaners.

 

Wool and cotton can withstand heat but heat can "kill" rayon yarns (a technique frequntly used by machine knitters for the drape that can happen with yarns that are "killed".

 

Pressure during the blocking of mohair usually results in the flattening of the small protruding hairs and negatively impacts the final appearance of the garment.

 

Once you determine that water can be used, do you immerce the whole piece or just lay it out and apply steam?

 

And do you block the individual pieces or wait until seaming is done and block the whole garment?