How to Block Knitting

Fill a clean sink or a basin with room temperature water. Not warm, not cold. Heat plus movement is what felts wool, so tepid is the safe setting and it costs you nothing. Lower the sweater onto the surface and let go of it.

Plain water is enough for a block. A capful of no-rinse wool wash softens the fibre and leaves a light scent, and you never have to rinse it back out, which is the whole point of the stuff.

A dry knit is full of trapped air, so the sweater rides on the surface like a raft. Put your palms flat on it and press it under, moving across the whole garment until the sleeves and the collar are all sitting below the waterline.

Hold it down in one spot at a time rather than rubbing or swirling it around. Agitation is what mats wool fibres into felt. Once the sweater stops pushing back, leave it alone for 15 minutes so the water gets right into the core of every strand.

Lift the sweater out as one bundle with both hands under it, so the weight of the water is not hanging off the shoulders. Press it against the side of the basin, then lay it on a dry towel, roll the towel up like a sleeping bag and lean on it.

Unroll it onto fresh dry towels, or onto foam blocking mats if you own a set, and open the sweater out to roughly the right shape. Put the pattern page down next to it so the finished measurements are in front of you.

Pull the tape straight across the chest from one underarm to the other. Laid flat you are measuring half the body, so a pattern that says a 35 inch bust wants 17.5 inches across the towel.

Short of the number? Walk the side edges outward with your fingers until it lands. Over it? Push the sides in. Wet stitches slide against each other, so the fabric goes where you put it and stays there once it dries.

Stand the tape on its end at the underarm and run it up to the top of the shoulder. That is your armhole depth, and on a raglan it decides whether the sweater sits on your shoulders or slides off them.

Hers came out at about 9 inches against a schematic asking for 8. One inch of extra drop sounds like nothing written down and reads as a sloppy fit on a body, which is exactly the sort of thing blocking exists to fix.

Push the underarm up with one hand and draw the shoulder down with the other until that extra inch is gone. The fabric bunches where you compressed it, so flatten the bubbling by patting the surface and pressing the stitches closer together.

Measure, adjust, measure again. Two or three rounds is normal. If an edge keeps creeping back, a few rust-proof T-pins through the fabric into the towel or a blocking mat will hold it there until it dries.

Run your fingers around the neckline and look for corners. A neck edge that came out angular instead of round dries that way, and no amount of wearing it will talk it into a curve later.

Push the high points down and coax the edge into one continuous line, then pat the ripples flat behind your hand. The collar sits under everybody's chin and it is the part of a sweater people look at, so give it the extra two minutes.

Measure from the underarm to the cuff on one sleeve, then do the other one. Sleeves knit weeks apart often come off the needles a half inch out of step, and this is the last chance you get to even them up. Stretch the short one gently until the two numbers agree.

Then stop touching it. Leave the sweater flat and undisturbed until it is bone dry, which is a day for a light knit and two or three for a dense wool one.