Science of Stitchery: Mathematics

This week it seems that I have been surrounded by numbers at work and at home. Mileage, yardage, gas tank capacities, bank accounts, dress sizes, and stitch count/fabric conversions. Then Saturday night I met a young lady working on her degree in mathematics. It took me back to my school years (a few decades ago) when I wondered why I had to learn all those formulas. No way was I EVER going to need them. Who knew I would use my math skills almost daily at Nordic Needle? UFF DA! (Uff Da is a Scandinavian sentiment that roughly translates to "I am overwhelmed". – reference link)

Several readers have asked me to do a newsletter explaining fabric conversions, estimating thread needs, and colorfastness of threads. Today I am going to try to combine them all into one newsletter called……

The Science of Stitchery


What is Colorfastness? The Textile Glossary says "The quality of a dyed material possessing resistance against washing, bright light exposition, or by rubbing." These three things are very important when planning a stitching project. It is something I didn’t think too much about until I was washing my piece to finish it and a thread bled onto the fabric and never quite came out. Here are some things you can do to try and avoid my mistake.


I talked about colorfast as it relates to threads briefly in the Surface Embroidery newsletter.

"Technically, no thread is completely colorfast. Some of the thread companies do make notations on their thread tags. For example: Crescent Colours Hand Dyed Floss says “Not Colorfast”. Weeks Dye Works has a statement “It is NOT COLORFAST. It must be washed…” Gloriana Silk says “Hand-washable in cold water. Dark colors and reds may bleed.” Simply Shaker Sampler Threads has this statement on the back of the label “our sampler and simply shaker threads are colorfast, however, we recommend ….rinse threads in hot water BEFORE stitching.” Splendor says “Hand Washable, but test first.” Subtlety said "Normally Hand Washable, Test First." Both DMC and Anchor Pearl Cottons say they are colorfast on their labels. EdMar rayon threads also indicate they are colorfast."

That does not mean that one time they won’t bleed when washed especially the darker colors that have more dye in them. It is best to always test your threads if there is any chance your piece will be washed when it is done. Here is a way to test your threads.

Materials Needed:

  • White paper towel
  • Length thread (Be sure to use a large enough sample like 6". If the thread is overdyed or variegated cut a piece that includes all the colors)
  • Cool Water (some people use distilled water. I use whatever water I would be washing the project in later – usually my tap water. Also hot water can reactivate your dyes, so I stick to cool water. However, one of the thread companies recommends using hot water. Follow the company guidelines if they are given.)

Wet your paper towel with water. Wet your threads and then lay them on the towel spacing different colors apart. Fold the paper towel over the threads, making sure they remain in place. When the paper towel is dry, carefully open the towel and pick up each thread. Look to see if there is any color on the paper towel. If there is, the thread is not colorfast. You may still be able to use this thread, but you will need to wash it.

Yes, this is a more time-consuming method than some people recommend. (Wet your threads thoroughly and then squeeze with white towel.) I much rather spend a few more minutes making sure my threads are safe before spending months stitching and then ruin it in finishing.

Preparing non-colorfast threads – by washing them

If you really want to use that color and it has bled just a little, you might be able to rinse it out well enough using this procedure. You will need a glass baking dish. I purchased one just for my stitching use. Do not use one from your kitchen. Water, enough for soaking and for rinsing (running water). You will need the entire skein of thread.

I use a glass baking dish so I don’t get any reaction from metal or wood. Put an inch of cool water in the glass baking dish. Open your skein of thread and lay it in the water, making sure all of it gets wet. If you leave your thread in a loop rather than cutting it into lengths, you can use a coated twist tie loosely wrapped through the loop so it will stay untangled. Let the skein soak. Remember patience is a virtue, so try to leave it in the water for an hour. Rinse the thread thoroughly. Put fresh cool water in the baking dish and repeat this process until the water is clear. Repeat the paper towel test just to be sure you no longer have color bleeding.

TIPS: Remember that reds and darker colors will be more likely to bleed.

Stitchers’ Paradise has an informative article with tips on setting your threads.


You need to be aware of the quality of the beads you are using as well. Robin Atkins is a bead artist who has compiled a marvelous list of tips and tricks for working with beads. What you may not be aware of is that beads may not be colorfast, the coating may rub off, or they can tarnish. Here are a few of Robyn’s tips about the colorfastness of beads:

  • "Put a small number of beads in hot soapy water to soak. After a few hours, rinse, dry, and compare them to untested beads.
  • Set a sample group in direct sunlight for several days. Compare them to an untested group of beads
  • If you’re making something that will be washed or dry-cleaned, sew a few of each color of beads on a swatch of your fabric. Test by washing or dry-cleaning the swatch.
  • To test for tarnishing, mix a sample group with mayonnaise and let it sit for a day or two. Rinse off the mayonnaise and compare to a group of untested beads."


Your fabrics can be slightly different colors between millings. If you are going to be stitching companion pieces, be sure to buy enough fabric from the same bolt to do all your projects. Something you may not have thought about is that fabric threads, especially in linens, will vary across the fabric. So, say you are doing the 5-part Nativity piece (NAT116) you may want to lay out your pieces across the fabric so the weave and threads will carry across all 5 pieces.

Dark colored fabrics can also bleed. If your project is going to be washed, you may want to wash it before you start stitching. Some fabrics, such as Monks cloth, require that you was them before you stitch.



What is meant by fabric count? This is the number of woven fabric threads per inch. For even weave fabric, the count should be the same whether horizontal or vertical, weft or warp.

Often a designer will list the fabric requirements as 14-count Aida or 28-count Linen.

This means you can stitch the design on 14-count Aida going over one fabric thread or 28-count Linen going over 2 threads. Here are the typical conversions from Aida to Evenweave:

  • 12 count Aida = 24/25 count evenweave
  • 14 count Aida = 28 count evenweave
  • 16 count Aida = 32 count evenweave
  • 18 count Aida = 36 count evenweave


Remember if you are substituting for a kit, be careful about changing the fabric size. You may run out of thread if you make your design size larger, such as using a 14-count instead of 18-count. However, you should be fine if you go smaller say from a 14-count to a 16-count fabric.

Another tip if you are using a kit and you know that you do a lot of ripping. Often the kits won’t list the color numbers for the floss. Lay out the floss from the kits and match it to floss in your stash or on a color card. Make a note of that number on your pattern key. I cannot count how many times we have had people come in asking for help in matching a color because they ran out. Another suggestion is to always keep a snippet of each thread that could be used for matching later. It is amazing how much different a thread will look by itself than when it is stitched.

When substituting Aida for an evenweave, remember that because of the way the fabric is made, it is harder to use Aida for certain techniques such as Hardanger embroidery or designs with specialty stitches.


Design Size versus Stitch Count

Design size refers to the size of the stitched area, not the finished size. Stitch count is the number of stitches (fabric threads) used in each direction. This is not the total number of stitches completed. Another important aspect is to know how many fabric threads you are stitching over. Depending on the designer, you may have one or both of these measurements listed on the pattern.

How to figure size if you only have stitch count:

Your design says it has a stitch count of 140 x 200, so how much fabric should you buy? First make sure which direction those numbers represent. In our web descriptions we try to show it as width x height (140w x 200h). Some designers will show it as 200h x 140w and others have it marked "h" for horizontal and "v" for vertical.

This means the design at its widest point is 140 fabric threads wide by 200 fabric threads high if stitched over one fabric thread. To determine the size in inches you need to know the count of your fabric and the stitch count.

The formula to figure stitch count:

Stitch count divided by (/) Fabric Count multiplied by (*) number of fabric threads stitched over equals (=) Number of inches for design area

Our Example of 140 x 200 on 28-count fabric over 1 thread would give us:

Width: 140 / 28 * 1 = 5"

Height: 200 / 28 * 1 = 7.14" or approximately 7 1/8"

Our Example of 140 x 200 on 28-count fabric over 2 threads

Width: 140 / 28 * 2 = 10"

Height: 200 / 28 * 2 = 14.28" or approximately 14 1/4"

NOTE: This is would be the same design size as the one stitched on 14-count fabric

Our Example of 140 x 200 on 14-count fabric over 1 thread

Width: 140 / 14 * 1 = 10"

Height: 200 / 14 * 1 = 14.28" or approximately 14 1/4"

How to figure size if you only have the design size:

If you want to change fabric counts, you will need to know the stitch count. Sometimes the designer only gives you the design size. Here is what you do to get the stitch count.

Our design is 22.5" wide by 12" tall and we want it to be smaller, so we want to change from 14-count Aida to 18-count Aida. First we have to find the stitch count.

The formula to find the design size:

Design size multiplied by (*) the fabric count divided by (/) number of threads stitched over equals (=) the number of stitches.

Our Example of 22.5" x 12" on 14-count fabric over 1 thread

Width: 22.5 * 14 / 1 = 315 stitches

Height: 12 * 14 / 1 = 168 stitches

Our Example of 22.5" x 12" on 28-count fabric over 1 thread

Width: 22.5 * 28 / 1 = 630 stitches

Height: 12 * 28 / 1 = 336 stitches

Our Example of 22.5" x 12" on 28-count fabric over 2 threads

Width: 22.5 * 28 / 2 = 315 stitches

Height: 12 * 28 / 2 = 168 stitches

So how do we figure our design size if we change the fabric count?

For this example, the stitch count is 315 x 168. It is 22.5" x 12" on 14-count. What will it be on 18-count Aida stitched over one thread?

Our formula would be:

Stitch count divided by (/) fabric count multiplied by (*) number of threads stitched over = design size.

Width: 315 / 18 * 1 = 17.5"

Height: 168 / 18 * 1 = 9.3"

What if you wanted to stitch the picture on 28-count Linen stitched over one thread?

Width: 315 / 28 * 1 = 11.25"

Height: 168 / 28 * 1 = 6"

What if you wanted to stitch the picture on 32-count Linen stitched over two threads? Width: 315 / 32 * 2 = 19.68"

Height: 168 / 32 * 2 = 10.5"

So here are our options from above:

On 14-count it is 22.5" x 12"

On 18-count it is 17.5" x 9.3"

On 28-count it is 11.25" x 6"

On 32-count it is 19.68" x 10.5" (but over two threads)

Tip: Remember, this is just for the DESIGN AREA. It does not allow for any fabric to put in a stitching frame or hoop. It is recommended to have at least 2"-3" all the way around your piece. PLUS: how much fabric will you need for your finishing technique? If the piece is to be framed then you need to take into account the width of the mat(s) and an inch or more for the framers to stretch the fabric on the back.

For a pillow determine the dimensions of the final pillow and then add at least an inch all the way around for the stitching.

Okay, I know some of your heads are spinning. Math is the class you skipped whenever you had the chance….I know because I skipped a few myself.

Don’t worry, there are some great conversion sites on the Web:


This is a question we get in the store frequently. It is one of the hardest ones to answer. Many things play into it like the stitching type, specialty stitches, how many plies or threads to use. Plus one of my big issues—how many times will I rip it out before I get it right!!??

All About Needlepoint has a wonderful guide on line.

These guidelines are for needlepoint, but some of the basic principles apply. I do stitch a small area when I begin to design a piece also to see how the threads look stitched and in context with the other colors/stitches. From now on, I will pay more attention to how much thread went into that area to see if I can guesstimate thread needs.

TIP: It is important that you buy plenty of threads especially if the color is dye-lot sensitive. It is amazing how much a color can vary from shipment to shipment. It is next to impossible to find another skein of a particular dye-lot once it is sold out. In addition, thread companies don’t always keep a color in their line. I know I have bought materials for a project with the good intention of stitching it right away (well, okay, this year). Then when I actually do start stitching it, I may find that the thread I need is no longer manufactured. So, buy plenty – it’s only money and we can’t take it with us. Well, at least that’s my motto!

Some of the graphing software available today creates a chart showing the number of stitches used by color. This can be daunting to look at! I shared this story before about my father and his stitching experience. He is a retired chemical engineer for Goodyear Tire and Rubber, used to dealing in numbers and formulas daily. He bought a Gold Collection cross stitch kit. He stitched and stitched and stitched and finally completed an inch area. For some reason, he needed to know how long it would take to complete the project. He took the number of hours that it had taken him to stitch that inch square. Then figuring how many stitches were in that inch, he came up with how many stitches he did in an hour. From the design size, he determined how many stitches there were in the finished project (it was solid coverage). It would take something like 235 days, stitching 8 hours a day, 6 days a week! Not a great way to motivate me to start a project.

But, for those of you who are inclined to do something similar, here is some data obtained from Classic Cross Stitch. For floss, using 2 ply, here is the estimated number of stitches you can get from one skein of an 8 meter (8.7 yard) skein of thread.

Stitches per inch Generous amount Average amount Thrifty amount
18 1800 2000 2300
16 1600 1800 2050
14 1400 1600 1800

Thank you for sticking in here with me! I am hoping I was able to pass on at least one tip or idea to make your stitching experience more enjoyable.

We hope this guide makes your stitching easier and more enjoyable!

For those interested in using this article or others published by Nordic Needle, Inc., please use this copy when referencing the information:

“The following article was written by Debi Feyh of Nordic Needle and published in their weekly e-mail newsletter. Permission was granted by Nordic Needle to share this article in (name of your publication). For information on subscribing to their weekly e-mail newsletter, visit A free mail-order catalog is available to you upon request if you live in the USA or Canada.”

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