I was starting a new knitting project, and came across something I’d never seen before. The instructions gave the gauge “in the round.” Since I was with my knitting group when I read this, I asked if it really mattered whether the swatch was knit flat (by going back and forth) or in the round (using either circular or double-pointed needles to knit a tube).

The answer was “It depends.” Apparently, many knitters have different tension for their knit stitches (the even rows of stockinette stitch) and their purl stitches (the odd rows). When knitting stockinette stitch in the round, you never have to purl, thereby avoiding this problem.

The result of different tension for your knit rows and purl rows is called “rowing out.” I had never heard of it or observed it before, but I was curious. I decided to knit some swatches flat just to see if I had this problem. My first try, I was astonished to see that I clearly had tighter purl stitches than knit stitches. How had I failed to notice this before?

At first, I tried to fix my problem just by paying attention. I tried to knit more tightly and purl more loosely. No luck. When I complained this wasn’t working, a friend suggested using a larger needle for the tighter rows. I wound up using a 2.0 mm for my knit rows and a 2.5 mm for the purls. Problem solved.

My eyes opened to this phenomenon, I dug through some past knitting to see if it had happened before. A flat swatch I had made in January showed obvious rowing out that I hadn’t noticed at the time. Intrigued, I decided to experiment and see what it would take to make a smooth swatch with this yarn. Since I didn’t know for sure which needles I’d used for that swatch (oops), I unraveled the swatch and started from scratch.

Almost as surprising as finding I had rowing out in my past work was my inability to reproduce the problem. I made two swatches with the same pink yarn using different sized needles made of different materials, and neither showed the obvious rowing out the swatch I frogged had.

I learned three important lessons.

The first is that there’s always more to pay attention to when it comes to knitting. Just because I’ve been knitting for decades doesn’t mean I begin to know everything about it.

Secondly, it’s easy to be blind. If you had asked me before I learned about rowing out, I would have bragged to you about my amazingly even tension. The fact is that I do most of my knitting in the round, so I was unaware my purl stitches were not the same tension as my knit ones.

Last, the details matter. The weight of the yarn, the size of the needles, and the material the needles are made of are all factors that affect the tension of my knitting. That means I have to pay attention to what I am using if I want to know for sure how a project is going to look when its completed.

And that means, like it or not, I better make a swatch.

What have you learned from making swatches?