Why crochet curls, cups and ruffles

A piece that should lie flat and does not is nearly always a counting problem. Crochet fabric has no memory of the shape you intended; it takes the shape that its stitch counts make. Learn what each distortion means and most of them can be fixed in a few rounds.

Cupping circles

A flat circle needs six more stitches each round with single crochet. Round one has 6, round two 12, round three 18 and so on. If you add too few, the extra fabric per round is less than the circle needs and the edge pulls inward, forming a bowl. The cause is commonly a missed increase or an increase worked in the wrong place.

Test the piece by laying it on a table. If the edge rises, add the missing stitches in the next round, or, for a piece that has already grown, pull it back two rounds and rework with a corrected count. A bowl shape that curves slightly can also be the intended form: hats begin as flat circles and then stop increasing so the sides turn down.

Ruffling circles

If the edge is wavy and the centre flat, too many stitches were added. A ruffle is the same problem in reverse: the outside has more fabric than the circumference allows, so it folds. Count the round. If the pattern says 36 and you have 40, that is the cause. The fix is to rip back and follow the count. Taller stitches such as double crochet need more increases per round, about 12 instead of 6, because each stitch is taller and pushes the stitches apart, so a circle of double crochet that uses the single crochet count will cup.

Curling edges on rectangles

Straight pieces curl when one side of the fabric is tighter than the other. Single crochet worked in a row makes a fabric with a front and a back that are not identical, and the tight side pulls the edge toward itself. Common fixes:

• Add a border. One or two rounds of single crochet around the edge straighten it by adding an even, stable edge.
• Work in a stitch that is the same on both faces, such as moss stitch or the waffle stitch. Both are in the stitch database.
• Change to a larger hook for the last row before binding off.
• Block the piece. Pin it to the shape, dampen it, and let it dry flat; cotton and acrylic respond differently, and wool holds the shape better than cotton.

The sides of a rectangle slope inward

If the piece gets narrower as it rises, you are losing stitches at the row ends. Look at the turning chains. A turning chain that counts as a stitch must be worked into at the end of the next row; one that does not count should be skipped. Mixing the two methods in one project results in a slowly shrinking or growing edge. Decide on one method at the start and count stitches at the end of every few rows.

The opposite, where sides flare outward, is usually an extra stitch at the start of each row, often from working into the turning chain when the pattern says to skip it.

Wavy lines across a piece

If rows are straight at the start and then wave, the tension changed. A change in yarn, a break for a day, or a looser hand after getting comfortable all leave a visible change. Hook size matters more than anything else here; a swatch before starting lets you choose a hook that gives the fabric you want, and then you can use the same hook for the whole piece. The hook database lists sizes in metric and US so you can match.

Corners that do not sit flat

In a square worked from the centre in the round, each corner needs a group of stitches, often three double crochet with a chain between them, so the fabric turns 90 degrees. If corners bunch, there are too many stitches in the corner; if they pull in, too few. Check that each side has the same stitch count, since a square with an uneven side will cup.

Yarn and hook effects

Even with the right counts, some combinations curl. A heavy drapey yarn, such as cotton, works in a dense fabric that resists curling less than wool does. A very small hook on thick yarn makes a rigid fabric that refuses to drape. As a rule, go up a hook size if the fabric feels like a board and curls at the edges, and down if it is loose and flimsy and ripples.

Using the photo tool

If you have a piece in hand that curls and you cannot work out why, the curl tool in the tools section accepts a photo and suggests the most likely cause and the fix, which is helpful when you inherit a piece or cannot tell which round went wrong.

Summary of causes