How to Knit a Helpful Swatch – Part 4 Swatching to Estimate Yardage Needed

August 24, 2020| LindyBeir| 0 Comment | 8:00 am

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I have covered the basics of how to make a Gauge Swatch and calculate your stitch and row gauge in my previous three posts. Today’s topic will cover some basic math to help you estimate the yardage that you need using your yarn, your needles, and your gauge to make a sweater.

Let’s say you want to make a sweater using yarn from your stash and you need to know if you have enough to make it. To make this estimate, you need the measurements for the sweater you want to make. If you are using a pattern, the finished measurements should be stated within the pattern – ideally on a schematic. Some patterns may only state the desired measurements within the text of the pattern and you may have to read through to find them. If you are making the sweater without using a pattern – you would use the measurements of the individual who will be wearing the sweater.

The image below shows a schematic for the back of a sweater of a drop sleeve sweater. The back is 28 inches long from the hem to the neck and it is 20 inches wide. Both the front and the back of this type of sweater are essentially rectangles.

The schematic for the sleeves of this sweater are shown below.

At this point, you have the numbers you need to calculate the number of square inches of fabric that you need to make for this sweater. For the front and back, multiply the length by the width on the schematic and then multiply that number by 2. Using the numbers from my example above:

20 * 28 = 560 560*2 = 1120 square inches for front and back.

The sleeve is a trapezoid shape. The formula for the area of a trapezoid is:

[(b1+b2) * h] / 2

Where b1 is the width at the bottom of the sleeve(8”) and b2 is the width at the top of the sleeve(15”) and h is the length of the sleeve(18”). Using the numbers from the sleeve schematic, the area for one sleeve is 207 square inches. Since you need two sleeves, you then need to multiply the area of the sleeve by two. (414 square inches)

Now, here’s a short cut – if you place your sleeves next to each other so that the tops of the sleeves are parallel – you have a parallelogram. To get the area of this parallelogram you simply multiple the width(15”+ 8” = 23”) by the length(18”). Try it – you’ll get the same number as above.

Add the square inches for the front and back to the square inches for the sleeves and you have the total number of square inches of fabric in the sweater. Now that you know the total number of square inches of fabric you need, you will need to use the yardage and weight information of the yarn you want to use to estimate how many skeins or balls of yarn your sweater requires. The yardage per weight of the yarn will be found on the yarn label – see image below:

You will use the yards per gram value in the estimate for total yardage. Now you need to knit a swatch. The swatch should be in the same stitch pattern that you plan to use for the body of your sweater. This swatch does not need to be the same size as your gauge swatch, but it should be wide enough and long enough to get an accurate weight, length and width measurement. After you knit this swatch, you will measure its weight using a scale that measures to the nearest tenth (0.1) of a gram. Next measure the length and width of the swatch and multiply these values together. This gives you the number of square inches in your swatch. Now divide the number of grams by the number of square inches.(Do not round). You now know what 1 square inch of your yarn weighs. This is the number you need to calculate how much yardage you need for your sweater.

Example: My swatch measures 3.5 inches by 4.5 inches, which gives me 15.75 square inches. The swatch weighs 9.6 g. Dividing 9.6 by 15.76 gives me 0.622 g/square inch.

Here’s the final set of calculations:

Take the total number of square inches of fabric and multiply it by the number of grams per square inch. This gives you the total weight in grams for your sweater.

Total Number of Square Inches * grams/inch² = Total grams of fabric

Total Grams/Square Inches = (1120 + 414) * 0.622 = 954.148 g

Now take the yards per gram value from the yarn label. (For example 218 yds/100grams). Divide the yds by the grams to get the number of yards in 1 gram of yarn. (For example: 218yards/100grams = 2.18 yards per gram.) Multiply the total number of grams of fabric by the number of yards per gram to get the total yardage for the sweater. Using the numbers from the examples above:

Yards per gram = 2.18 yds/g

Total Yards of Yarn = 954.148 * 2.18 = 2080 yds

To determine the number of skeins, balls or hanks of yarn you need: Divide the number of yards by the number of yards in the skein. Or divide the total number of grams by the number of grams of the skein. Remember that you will want one extra skein for swatching. (In my example, I would need 9.5 skeins, so I would want 11 skeins with one extra for swatching)

What to do if you don’t have the yarn label

To determine how many yards of yarn you have when you do not have the yarn label or any information, simply measure out 10 yards of your yarn and weigh it. Divide the weight by 10 and you have the weight for 1 yard of yarn. Now weigh the skeins/hanks of yarn and multiply by the weight of 1 yard. This will give you the number of yards for each skein/hank.

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Book Review: Knitting Plus by Lisa ShroyerBook Review: Knitting Plus by Lisa Shroyer

May 13, 2012| LindyBeir| 0 Comment| 8:00 am

The subtitle for this book is “mastering fit + plus-size style + 15 projects”. The first two chapters of this book cover the basics of how to knit garments that fit. While the focus is on plus-size, the information is applicable to any knitted garment. The information in these two chapters is worth the price of the book if you are wanting to learn more about how to modify patterns so that they actually fit your body. Chapter One discusses the common elements of a sweater and “what they mean to you” and Chapter Two covers the use of measurements and how to redesign patterns for a custom fit.

The remaining five chapters cover different types of sweater styles: The Drop-Shoulder, the Set-In Sleeve, The Raglan, The Seamless Yoke, and The Dolman. There are three projects for each type and these are really lovely designs for us plus-size gals. Each project also has helpful notes for the knitter. So this book is both a “how-to” guide and a set of 15 plus-size patterns. And some of those patterns are the sort that makes a knitter’s fingers itch to pull out some yarn and needles and get started. The “Poppy Cardigan” on page 67 is on my list of future projects for sure.

If you are interested in this book, click on the picture at the top of this post. It will take you to the book on Amazon.com.

Stitch Pattern: Elfin LaceStitch Pattern: Elfin Lace

October 19, 2010| Lindy| 5 Comments| 9:00 am

The Elfin Lace pattern was used in Dishcloth #5 in my Summer Knitting project. This is an easy eyelet lace pattern made with a combination of yarn-overs and right and left leaning decreases.

The Elfin Lace pattern is a multiple of 8 stitches plus 9 done over 16 rows.

Row 1: (Wrong Side) and all wrong side rows – Purl.
Row 2: K2, *YO, SSK, K6. Repeat from *, end last repeat K5.
Row 4: K3, *YO, SSK, K3,K2tog, YO, K1. Repeat from *, end YO, SSK, K4.
Row 6: K4, *YO, SSK, K1, K2tog, YO, K3. Repeat from *, end YO, SSK, K3.
Row 8: K2, K2Tog, *YO, K5, YO, Slip 2 knitwise, K1, Pass 2 slipped stitches over. Repeat from *, end YO, K5.
Row 10: K6, *YO, SSK, K6. Repeat from *, end YO, SSK, K1.
Row 12: K4, K2tog, *YO, K1, YO, SSK, K3, K2Tog. Repeat from *, end YO, K3.
Row 14: K3, *K2Tog, YO, K3, YO, SSK, K1. Repeat from *, end K2Tog, YO, K4.
Row 16: K5, *YO, Slip 2 knitwise, K1, pass 2 slipped stitches over, YO, K5. Repeat from *, end YO, K2Tog, K2.

Repeat rows 1-16 for the desired pattern length.

Reference: Barbara G. Walker, A Treasury of Knitting Patterns

A Study of Pooling in a Variegated Sock YarnA Study of Pooling in a Variegated Sock Yarn

May 5, 2010| Lindy| 0 Comments| 12:38 pm

Several days ago, I decided to knit a pair of plain vanilla socks using Serenity Sock Weight Yarn (Premier Yarns) in the colorway Amethyst. This was a yarn I had purchased at my local Hobby Lobby and had been sitting in my sock yarn stash for a few months. In the skein, the yarn appears to be a mix of greys and purples, and I thought it would result in a striping of the socks. The label does not indicate that the yarn is “self-striping”, but the picture on the label shows a sock with an interesting variation of stripes.

Since I had never knit with this yarn, I knit a circular swatch to determine needle size and gauge before starting on my socks – and this is where my study in “Pooling” began. I started with US 2 (2.75 mm) needles and cast on 64 stitches (which is what I would use for my socks with a gauge of 7 stitches per inch). As I worked on the swatch, I noticed that the yarn was not knitting up in the stripes the way I had anticipated – in fact, it seemed to be predominately purple on one side of the swatch and predominately grey on the other side.

Obviously, I had some “pooling “ going on. Pooling is an effect that occurs when a variegated yarn knits up in “pools” of color, rather than in stripes. Now, I wasn’t really sure I liked the effect – and my stitch gauge was 6.25 spi, rather than the 7 spi I wanted.

So, I decided to do a second swatch with fewer stitches, a smaller needle – and because I had read about pooling in a Rav thread, I also decided to knit from the outside of the skein instead of the inside. I cast on 52 stitches on size US 1.5 (2.50 mm) needles and knit away – and I got more striping – not even stripes, but definitely stripes on both sides of the swatch.

So, I took a picture of the two swatches and posted a comment on Ravlery under the thread, “Examples of Pooling Good & Bad”, stating what I had observed along with my assumption that the change was probably due to knitting from the outside of the skein – and completely ignoring the fact that I had changed the number of stitches in the swatch and this might also be contributing to the way the colors were knitting up.

I must admit, I did not anticipate much of a response to my comment in this thread. But I received several. It’s one of the things I love about Ravelry – fellow knitters are always willing to share and question things. Anyway – after reading the comments, I decided I needed to do a little more work before I could actually answer my fellow Ravelers’ questions.

Off I went to swatch again – this time I decided to start from the inside of the skein, use US 2 (2.75 mm) needles and begin by casting on 72 stitches. I knit approximately 1.5 inches, then purled and decreased the number of stitches to 64 stitches, knit another 1.5 inches, purled and decreased to 54 stitches and knit another 1.5 inches. Here’s a picture showing how the yarn pooled with different numbers of stitches.

So – in response to Robocass and Hypercycloid, who asked me if the difference might be due more to the difference in the number of stitches in my swatches: Clearly, the number of stitches used results in very different color patterning and it doesn’t really matter whether I knit from the inside or the outside of the skein.

Hypercycloid also asked about the length of each of the colors in the yarn. Hmm – I hadn’t thought about that, so I got out the measuring tape and discovered that each purple section of the yarn was approximately 19 inches, while the grey sections were approximately 12 inches. Not quite, but almost a 3 to 2 ratio. Statnerd suggested I count the number of grey stitches compared to the purple stitches in my wider swatch – I did and ended up with 27 stitches of grey to 37 stitches of purple. Again, this is close to a 3 to 2 ratio of purple to grey. All of you were correct in your observations that the colors shift around the circumference of the swatches – and due to the differences in the number of stitches, the colors stack up very differently for different numbers of stitches.

Zgma commented:

“It doesn’t look like a self-striping yarn to me. The striping you got in the top sample is a result of the colors pooling in a way that looks like stripes, not actual “self-striping”. When yarns are labeled self-striping, it is because the runs of color are large enough that for the project intended (as in, socks for self-striping sock yarn), the color will last for all the stitches in at least one round or row, usually more. When a particular color (for instance, the black in your sock samples) lasts for part of a row, but then in the next row the color occurs before or after it did in the previous row in such a manner that it looks like striping, it doesn’t mean that the yarn is self-striping – just that it is prone to pooling in a stripey way.”

Yep, you are right about that.

To each of those that took the time to comment — thanks! I learned a great deal about pooling and variegated yarns.

I did a little internet surfing on the subject, as well. I found two informative posts about Pooling — One from the Yarn Harlot and the other from Knitting Sutra.

So – I am not really sure if I like this particular yarn – but I have decided to proceed with using it to knit a pair of plain vanilla socks. I am going to use US 2 (2.75 mm) needles with a gauge of 6.25 spi and cast on 54 stitches (this should fit my foot). I’ll post pictures of the final result.