Sunday, December 21, 2008

Recalculating a Pattern

Happy Hanukkah! I hope everyone is enjoying the holidays and may all your projects be finished!

I ran into a small problem this week with a last-minute project, and I thought I could share some words of wisdom with all of you.

My husband, who never ever wants me to give him gifts, was finally, with much arm-twisting, persuaded to let me knit something for him. His request? A felted vest. I searched through some patterns and came across the Felted Vest pattern in Bev Galeska's wonderful book, Felted Knits. Just one problem. With only a week to go before the big gift-giving day, I realized that I really, really didn't want to spend hours and hours each day knitting nine miles of stockinette stitch, only to felt it later.

Now don't get me wrong - I love knitting. I love knitting gifts for my husband. I love felting. But to spend so much time knitting something the size of a long winter nightgown and then shrink it to the proper size would take a whole lot of knitting time. Time that I could spend doing really interesting knitting, like cables and lace and other fascinating things.

Not a problem though, because I have a basic knitting machine for just such an emergency. I like to do a lot of felted projects, and I have been playing with the knitting machine exclusively for this very purpose. My first job, then, in changing the pattern from hand-knitting to machine knitting was to knit up a swatch on my machine at the tension settings that I know from experience will give me a fabric that felts easily and well, and then measure the gauge of that un-felted swatch. The pattern calls for a gauge of 14 sts/4 inches and 21 rows/4 inches in an un-felted swatch. And my machine, wide open, only gives a gauge of 15 sts/4 inches and 21 rows/4 inches. That is as big as it gets, the machine won't make stitches any larger than that.

My husband piped up and asked the question that perhaps some of you are asking as well: It's only one stitch difference. What's the problem? Ah, but it's one stitch over four inches. Multiply that tiny little stitch by the total size of the unfelted vest, and you've got a project that doesn't fit when it's finished. At the stitch count that the pattern calls for, and knitting at my gauge, the vest would end up significantly smaller than intended.

Now say that like many of us, you see a pattern you love and there is a wonderful yarn at Kiwi that you have been just dying to use - but it doesn't quite fit. Or you are looking for a pattern to help you use up something that has been gathering dust in your stash. And your substitute yarn knits up at a different gauge than the yarn that the pattern calls for.

Or maybe you have the specified yarn, but you don't like the look of the fabric at the proper gauge. The swatch might feel too loose and open to you, or so tight that you could use it to scrub pots and pans. What do you do? Give up and move on to another project?

No. You recalculate your pattern, taking into account the gauge you are going to be using. The process is very, very simple, but it does contain several steps. Follow these simple steps and you are on your way to a successful project.

First of all, we know that gauge x size = stitch count. The number of stitches you get to the inch, times the size you want the project to be when finished, tells you how many stitches you need to cast on.

It wouldn't be appropriate for me to talk about the actual stitch count in the pattern that I used, so I am fudging that part a bit in my explanation, but all the rules are the same - no matter what the original gauge is, what your gauge is, or what the stitch count is.

1. Knit your gauge swatch and determine your new gauge.. Measure your stitch gauge and your row gauge. Write them down. Block your swatch. Measure the stitch gauge and row gauge again after blocking. Write them down. Why do I tell you to measure gauge before and after blocking? Your post-blocking gauge will guide you in getting the proper finished results. Your pre-blocking gauge provides you with a guideline to maintain as you are knitting, to ensure that you are staying on gauge and will get the results that you want. Because I am felting the finished project, that point is moot in my example, but it sure the heck won't be moot in your non-felted project. Take the time to take both before and after measurements and be a happier knitter.

My gauge = 15 sts/4 in. 21 rows/4 in.
Let's break that down into inches by dividing by four- 3.75 sts/in.

2. Find the pattern's original gauge requirement.
Original pattern (OP) gauge = 14 sts/4 in, or 3.5 sts/in. 21 rows/4 in.

My row gauge and the OP row gauge are the same, so we can ignore them, nothing needs to change there.

3. How many inches is the finished size of the OP?
In my example we will pretend that the original pattern for a 40-inch finished size is asking me to cast on 140 sts. If we do the math, we know that 140 sts divided by 3.5 sts/in = 40 inches. Or, 3.5/140=40.

4. Substitute your new gauge.40 inches x 3.75 sts/in = 150 sts to cast on.

This means that I have to cast on 150 stitches at my new gauge of 3.75sts/in in order to get a 40" chest measurement in my final garment.

Still with me? Good.

Okay, you cast on 150 stitches and knit up to where the armhole shaping starts. Now the original pattern asks you to bind off 9 stitches at the beginning of the next row. Divide nine stitches by the original gauge of 3.5sts/in and that is 2.57 inches to cast off in the OP. Let's multiply that 2.57 in. by my new gauge of 3.75sts/in, and I know that I have to cast off 9.64 sts in order to get the same decrease depth. Let's just call that 10 stitches and be done with it.

Next the pattern asks me to cast off 1 st at the armhole edge, every other row 6 times. That adds up, of course, to 6 more sts decreased. 3.5/6 = 1.71 inches. In order for me to achieve the closest equivalent, I then multiply that OP 1.71 inches by my 3.75sts/in and know that I have to cast off 6.42 sts. That can't happen, so I'll stick with 6 sts to cast off.

And so on. When the original pattern tells you to do something - bind off, cast on, whatever - for 'A' number of sts, divide 'A' by the OP sts/in in order to get the most basic unit. Next multiply the result of that by your new sts/in, and round the new result up or down accordingly. You'll get your desired fabric and size using your new gauge, and you'll be happy with the results.

1 comment:

Michelle said...

While working on my daughter's blue sweater (remember that yarn, Linda?), I learned another trick for recalculating a pattern with a different gauge than is called for.

My daughter's pattern was written for 5.5 sts/inch, but as you noted, the resulting fabric was too gappy. It looked pretty good on a smaller needle at 4.5 sts/inch. In Stitch 'n' Bitch, I read that you can take the pattern's gauge, divide it by your gauge, and that will give you a gauge ratio. In my case, i divided 5.5 by 4.5 and got a ratio of 1.2. Then wherever the pattern told me how many stitches I should have for the size I'm making, I just multiplied that number by 1.2. With increases and decreases, I plugged in the 1.2 wherever possible and fudged the rest.

The sweater is still in progress, but the completed pieces match the measurements the pattern calls for, so I guess it must be working.