example of a garter stitch tension patch example of a latice stitch tension patch

Tension (SH and SW)

In this section we are going to use a tension patch to work out average Stitch Height (SH) and Stitch Width (SW), the basic units of mathematical design.

Introduction

A tension patch is usually used to check that when you knit something (most likely clothing) the result is the same size as the pattern intended. ODDknit patterns rarely require you to knit a tension patch because they are designed to be small and fun, not wearable.

However when you design with maths you will need to knit a tension patch. You use it to work out the average width (SW) and height (SH) of a stitch. The process of mathematical design depends on being able to predict how many stitches you will need for a given shape – and how many stitches you will need depends on what size they are.

Knitting your Tension Patch

To begin the tension patch cast on at least 20 stitches.

Factors that influence the size of a stitch are the type of yarn, the size of needles, the knitting stitch and the tension with which you hold the yarn. Try to make all these the same in the tension patch as they will be in the final object.

Work around 30 rows and then cast off.

See increaseing accuracy for tips on how to get more accurate results for SH and SW.

Stitch Width (SW)

Measure the width (W) of the tension patch.

Measure the width of the tension patch.

Divide the width of the patch by the number of stiches that were cast-on (nW). This gives us the individual stitch width. As an equation this is written:

SW is equal to W divided by nW.

Stitch Height (SH)

Measure the height (H) of the tension patch from the cast-on edge to the cast-off edge.

Measure the height of the tension patch.

Divide the height of the patch by the number of rows (nH) with two added (we are averaging in the cast on and cast off edge into the stitch height). This gives us the stitch height. As an equation this is written:

SH is equal to H divided by nH add 2.