Seamless Knitting Trick

It’s no secret that I love seamless knitting. Often you’ll see seamless garments worked from the top-down, but you can also work seamlessly from the bottom-up. When working a pullover like this, your construction looks like this:
cast-on at hem > work the body in the round > split front and back at underarm > work each front/back separately, flat (i.e, working back-and-forth) up to shoulders. Here’s a diagram of this construction, using my Castaway tee as the example:

The one downfall of this construction…

Here is something I have learned along the way. My knit stitches are tighter than my purl stitches. How do I know this? I can see/measure my gauge difference between stockinette stitch in the round (i.e, knitting every round) and stockinette stitch flat (i.e, knit 1 row, purl 1 row). My flat gauge is always a little bit looser, so that tells me my purl stitches must be a bit looser than my knit stitches – and it turns out, I’m not alone! This is a very common occurrence.

But what does it have to do with bottom-up seamless construction? Well after you split the front and back at the underarm, you are no longer working in the round – you’re working each front/back flat, i.e, back-and-forth. So you switch from knitting every round to all of a sudden knitting 1 row and then purling the next. So if you are like me and your purl stitches are looser than your knit stitches, you’ll have tension discrepancies between the top part of your garment and the bottom!

There’s an easy hack to fix this

After you split your front and back at the underarm and you are working back-and-forth, simply use a smaller needle when working your purl stitches! So you’ll have 2 circular needles going, but it’s not as cumbersome as it sounds. It’s just the stitches are ‘resting’ on one of them as your work the next row with the other needle.

Or, if you are working on interchangeable needles, you can just attach the smaller needle tip to one of the ends and make sure it’s positioned so that it’s on the end that would be doing the purling.

It works for other seamless situations too

You can work this hack for other seamless constructions where gauge discrepancies can occur. The other most popular situation where this occurs is in seamless cardigan sleeves. Your cardigan body is worked back-and-forth but your sleeves are in the round – in this situation, you could try bumping up 1 needle size for the sleeves (but in this case you would work every round in this larger needle size).

Another situation is when you are working bottom-up but you have a split hem. So the split hem is worked back and forth, but then you join for working in the round. Similar to our main example here, you would work the purl rows of the split hem with a smaller needle.

Bottom-up seamless examples

I have quite a number of garments that are worked seamlessly from the bottom-up that you could use this trick for! Below is a selection of them: