The Knitting Fiend

On the knitlist, Deb, who wants to make a felted laptop bag, asks:

I have knitted a gauge swatch in garter stitch but read the laptop bag pattern in the latest issue of IK and it calls for St st. Does it make a different with felting what stitch you use?

I’m afraid it probably does. This is my experience:

Last year, I knit a felt purse with a garter stitch strap. As many people know, when you felt stockinette, it typically shrinks more in length than width. When a designer publishes a pattern, they count on a particular rate of shrinkage, and adjust the length and width of the unfelted object to shrink to the correct length.

In particular, when I felted garter stitch, I found it doesn’t shrink in length like stockinette; it may lengthen! That’s what happened with my garter stitch strap.

Now, I’ll admit I don’t know if the lengthening was due to the garter stitch or the fact that it was a long strap. However, I suspect the different shrinkage rate was due to it being garter stitch.

Here’s why:

Examine the garter stitch to the left; the ridges make the fabric “crunch down” and “be short”. It also makes the fabric very elastic, and you can stretch it a lot both in length and width. Notice, I can stretch the fabric vertically, and separate the ribs. It’s much stretchier in this direction than stockinette.

(By the way, garter stitch is notorious for grown in length under gravity for this reason; you can see the ridges sort of spread apart. Many complain about this after knitting the Einstein jacket, which looks great when new, but often grows if not knit firmly.)

Now, examine the garter stitch in the felted strap from my purse. My fingers are included to show scale; I’m not stretching the fabric.

First, notice, the fabric felted. However, it looks like the the garter stitch ridges first spread apart, then felted in a stretched state.

The net effect is: the strap didn’t shrink in length, it grew!

Now, remember I said I didn’t know if this unexpected behavior was due to the garter stitch being a knit as a long strap?

Well, if I took photos of the garter stitch trim at the top border of the purse, I didn’t notice this dramatic spreading of the ribs. They appear to have felted in their “unspread” state. So, it may be that the way garter stitch felts varies depending on whether it’s a long strap or a wide.

If so, felting garter stitch will always be somewhat unpredictable. That mean’s it will be difficult to know, in advance, whether a particular item will shrink to the intended dimensions. That means: the lap top bag might not fit.

Here’s my advice: I wanted a garter stitch felted cozy, I’d knit a swatch, measure it both before and after felting and then calculate to make sure the felted cozy would ultimately fit my laptop.

Afterwards, I’d hope for the best.