This is the fourth of five posts in a series on sewing ribbing.

Jump to half-stitch seaming in 1×1 ribbing, full-stitch seaming in 1×1 ribbing, or full-stitch seaming in 2×2 ribbing. (In this series, “half-stitch seam” means any seam consuming half a stitch from each edge, and “full-stitch seam” means any seam consuming a full stitch from each edge. See the first post for more information.)

The Options

There are three set-ups we can have for working public-side rows of 2×2 ribbing. We can

1. start with K2 and end with P2
2. start with K2 and end with K1
3. start with K2 and end with K2

Let’s take them in turn, and we’ll see with stylized stitches which one works best. (If your instructions have you start with P2, scroll to the bottom.)

Option 1: Start with K2 and End with P2

Here’s the seam at the wearer’s left.

 

The gray parts of the edge stitches

 

will be consumed by the half-stitch seam.

 

Now let’s “sew” the seam and see what results.

 

It might be hard to tell what’s happening, so here’s what it looks like with the three stitches removed from both ends.

 

Since we’re trying to join half a knit stitch to half a purl stitch, the result is going to be unattractive, so let’s move to the next option.

Option 2: Start with K2 and End with K1

The seam at the wearer’s left is

 

The gray stitch halves

 

will be consumed by the half-stitch seam.

 

When we “sew” the seam

 

we have a completely imperceptible join, because we put the left half of a knit stitch against the right half of a knit stitch, with the result that it looks like a whole knit stitch.

The other body side seam and the sleeve underarm seams will work exactly the same way.

Since we know this is the option we need, we don’t really have to see what happens with the third option. We’ll look at it anyway, just for completeness.

Option 3: Start with K2 and End with K2

Here’s the seam at the wearer’s left.

 

The gray halves

 

will be consumed by the half-stitch seam.

 

When we “sew” the seam

 

we wind up with three knit stitches in a row, which disrupts the flow of the 2×2 ribbing.

The Correct Option

If we want to do half-stitch seams in 2×2 ribbing, we have to make sure the ribbing’s public-side rows all start with K2 and end with K1.

Adjusting a Project’s Instructions

There are four different cases we have to think about, since 2×2 ribbing has a multiple of four stitches. The number of stitches we’re supposed to cast on might be

A) perfectly divisible by four, like eighty-eight
B) divisible by four with one left over, like eighty-nine
C) divisible by four with two left over, like ninety
D) divisible by four with three left over, like ninety-one

Let’s look at each possibility.

Possibility A: Perfectly Divisible by Four

If the instructions for 2×2 ribbing indicate a number divisible by four, we simply add one stitch to the end of our cast-on and keep it as public-side knit stitch.

So if we are supposed to cast on eighty-eight, which is perfectly divisible by four, we will instead cast on eighty-nine, then we keep the last stitch as a public-side knit.

Possibility B: One Stitch Left over After Dividing by Four

If we’re supposed to cast on, say, eighty-nine stitches, which when divided by four leaves one stitch as the remainder, then that’s perfect situation. We change nothing. We simply keep the last stitch as the public-side knit that it will naturally be when we’ve worked “K2, P2” all the way across the row.

Possibility C: Two Stitches Left over After Dividing by Four

If the instructions are for 2×2 ribbing on an even number of stitches but not a number perfectly divisible by four, like ninety, then we’re ending public-side rows with K2. We know that set-up won’t look right if we try to use a half-stitch seam on it, so we cast on one less stitch, just eighty-nine. We’ll start with K2 and end with K1 on public-side rows.
This possibility arrives at the perfect set-up of possibility B from the other direction than possibility A did.

Possibility D: Three Stitches Left over After Dividing by Four

If we had been instructed to cast on ninety-one stitches, this is the situation we’d be in, because ninety-one divided by four leaves a remainder of three. We have two choices:

1. We cast on two more stitches, which gets us back to possibility B’s “one stitch left over after dividing by four.”
2. We cast on two fewer stitches, which also gets us back to possibility B’s “one stitch left over after dividing by four.”

So instead of casting on ninety-one, we’d cast on either eighty-nine or ninety-three. Both those numbers have a remainder of one when we divide them by four, so they get us back to the perfect possibility B.

When We Start the Body or Sleeve

When we have completed the ribbing, we may be told to increase some number of stitches as we work across the first body/sleeve row. If so, then we may have to adjust the exact number of stitches we increase.

• If we had cast on one more stitch, then we increase one less stitch, because we already had an an extra stitch in the ribbing.
• If we had cast on two more stitches, then we increase two fewer stitches, because we already have two extra stitches in the ribbing.
• If we had cast on two fewer stitches, then we increase two more stitches, because our ribbing was already two stitches short.

If the Ribbing Starts with P2

I suppose there are sweater designs that start the ribbing with P2 instead of K2. All of the above will apply, except that we have to swap “knit” for “purl” and “purl” for “knit” everywhere.

Jump to overview, half-stitch seaming in 1×1 ribbing, full-stitch seaming in 1×1 ribbing, or full-stitch seaming in 2×2 ribbing.