Yarn Systems

Marcy Petrini

October, 2020

“How come, asked Laura, that the sett for this project is 24 epi when the sett from my previous project was 30 epi? They are both 20/2 and plain weave.”

The answer is that the previous project was 20/2 cotton and the current project is 20/2 silk.

But that’s no answer, really. The real answer is: the yarn systems. Just like the measures of length were developed in different places as the metric and the English systems, so each yarn production was limited to a region, and a local system was developed.

Below is the comparison for Laura’s and other 20/2 yarns. Yarns are usually labeled with two numbers; the first generally represents the size or grist of the yarn, the second number represents the ply, the number of strands twisted together. Thus all of the yarns listed below are 2 plies because they are all 20/2. But look at the difference in yards/lb.: the larger than number, the more yards to the lb., the thinner the yarn, the closer the sett.

 

Yarn 20/2	Yards/lb.	Warp Sett (epi)
Linen	3,000	24 - 30
Silk (Spun Bombyx)	5,000	24 - 28
Wool (Worsted)	5,600	20 - 30
Cotton	8,400	30 - 48

 

Today we don’t really need to know about the details of the yarn systems. Yarn vendors nicely tell us yards per lb. so we can convert our warp and weft length calculations to the amount of yarn weight we need to purchase. They even give us helpful hints for the appropriate setts.

But how do they get the information? From the yarn systems.

I first learned about the yarn systems from an article by Walter Houser called ”Yarn Counts” that appeared in The Weaver’s Journal, Fall 1983, on page 52. Other information is newer, and I often deduced it from what the vendors list for yards/lb. Tencel^®, and other yarns extruded form natural materials, for example, use the cotton count and so does cottolin. But the Houser article gives us the foundation.

The first number is the relationship between length and weight, either weight per unit length or length per unit weight. When the length is expressed in skeins, the actual length of the skein varies with the fiber. Here some of the most commonly used systems:

 

Yarn System	First # (for 1 ply)	Conversion Factor	Second #
Cotton	Skeins / lb.	840 yards (cotton count)	Ply
Worsted Bradford	Skeins / lb.	560 yards (worsted count)	Ply
Woolen	Skeins / lb.	1600 yards (run)	Ply
Linen	Skeins / lb.	300 yards (lea)	Ply
Dernier Silk Filament	Grams/length	9,000 meter (Den)	*Tolerance, high and low average
Jute	lb./length	14,400 yards (Spindle)
Novelty yarns	Yards/lb.
European System	Meters/grams

^* The tolerance is for silk before being degummed; ready for use is 25% to 30% lighter.

 

We can use the table above to obtain the same information that yarn vendors give us. Let’s use cotton as an example,

One lb. of a 1 cc (cotton count) yarn by definition is 840 yards long (single ply). This is the standard skein.

 

CC	Length	Weight
1 (or 1/1)	______________ <------------ 840 yards ----------->	1 lb.

 

A 2 cc yarn means that 2 skeins (each 840 yarns long) will weigh 1 lb. Thus, a 2 cc yarn has 1680 yards to the lb. (840 yd/skein times 2 skeins). This yarn is half the size of the 1 cc.

 

CC	Length	Weight
2 (2/1)	________________________________________________________ <---------------------------------- 1680 yards --------------------------->	1 lb.

 

In general, the larger the count, the smaller the yarn, since so many more “skeins” (each 840 yards for cotton) have to fit into a pound.

The above statements are true for 1-ply yarn. If we take the 1 cc skein and ply it into 2 strands, the yardage will be half, but the weight is the same. A 1/2 cotton yarn is 420 yards to the lb. The two-ply, of course will be thicker than the 1-ply of the same yarn count, but not double. Jill Duarte (Ply Autumn 2020, page 36) says that a 2-ply handspun yarn is about 1½ times the singles that make it up because of the strands winding around each other. The same must be true of commercial yarn.

 

CC	Length	Weight
1/2	=========== <------------ 420 yards ------------>	1 lb.

 

If we take a 2 cc yarn which has 1680 yards to the lb. and ply it into 2 strands, the yardage will be half, 840, for the same weight, back to the original yardage. The size will also be larger because there are 2 strands, but approximately 1½ times the size of the singles.

 

CC	Length	Weight
2/2	============ <------------ 840 yards ----------->	1 lb.

 

Let’s use an example from a common yarn, 8/2 cotton.

The “8” means that there are 8 skeins in 1 lb. of yarn, each skein 840 yards:

8 skeins x 840 yards/ skein = 6,720 yards

The yarn has been plied, which we know from the “2”, thus for 1 lb. our yardage is:

6,720 yards / 2 = 3,360 yards /lb.

Which is what we find listed from yarn vendors. Incidentally, mercerization does not change the cotton count.

Since a picture is worth a thousand words, here is a comparison of cottons. The gold is 3/2, the blue is 5/2 and the orange is 10/2, all mercerized. This is what our yarn vendors tell us:

3/2 cotton = 3 skeins x 840 yards/skein / 2 skeins/lb. = 1,260 yards/lb.

5/2 cotton = 5 skeins x 840 yards/skein / 2 skeins/lb. = 2,100 yards/lb.

10/2 cotton = 10 skeins x 840 yards/skein / 2 skeins/lb. = 4,200 yards/lb.

 

 

 

Note that 10/2 cotton has twice the yards/lb. than 5/2 cotton, as we expect.

Next time you purchase yarn, make sure you look at the recommended sett by the vendor and remember that the sett of two yarns with same numerical description won’t be the same if the fiber is different.

 

Happy weaving!

How Well Do You Know Your Twills? 

Marcy Petrini

August, 2020

When my Covid-19 quarantine started, I was some three weeks into an 8-weeks twill class I was teaching at the Mississippi Craft Center. Even after the locked down ended, the studio is way too small for social distancing. Eventually, we switched to zoom, with students either taking their warps home to weave it or going to the studio solo to finish the project.

How well did it go? I would say well, because at the end, I decided to have a final test and they did well! And next, we will zoom about lacey weaves.

Here is the beginning twill test – how well do you know your twills?

 

Twill Test (Choose the best answer)

>

1. The minimum number of shafts needed for a twill is:
   1. 1
   2. 2
   3. 3
   4. 4

 

2. Floats in a twill fabric are:
   1. Weft floats
   2. Warp floats
   3. Both warp and weft floats
   4. Depends on the twill

 

3. A standard tie-up is:
   1. 1&2; 2&3; 3&4; 4&1; 1&3; 2&4
   2. 4&1; 3&4; 2&3;1&2; 2&4; 1&3
   3. 1&3; 1&2; 2&3; 3&4; 4&1; 2&4
   4. All of the above

 

4. In an unbalanced twill:
   1. The fabric is warp-dominant
   2. The fabric is weft-dominant
   3. The fabric depends on the specific twill
   4. The fabric is warp-dominant on one side, weft-dominant on the other

 

5. Which cannot be woven on 4 shafts:
   1. Satin
   2. False-satin
   3. Broken twill
   4. Extended pointed twill

 

6. Which are possible weaving combinations?
   1. Straight twill threading, pointed twill treadling
   2. Pointed twill threading, straight twill treadling
   3. Undulating threading, broken twill treadling
   4. All of the above

 

7. A fancy twill is:
   1. An unbalanced twill
   2. An irregular twill
   3. A treadling method
   4. A twill with plain weave

 

8. Waffle weave is
   1. A treadling method
   2. Pointed twill
   3. Bird’s eye twill
   4. Popcorn weave

 

9. If the treadling step is 1&3, which is the “on opposite” treadling step?
   1. 1&2
   2. 2&4
   3. 2&3
   4. 3&4

 

10. Floating selvages:
    1. Should be used on the side where the weft doesn’t catch
    2. Should be used on both sides of the fabric
    3. Are not needed for twills
    4. Are needed for irregular twills

 

11. For a balanced fabric, the sett for a twill should be:
    1. About the same as for plain weave
    2. Slightly more open than a plain weave
    3. Slightly denser than for plain weave
    4. Depends on the twill

 

12. For a weft faced twill, which of the following are true:
    1. The weft covers the warp
    2. The color interactions provide the pattern
    3. A number of different twills can be used
    4. All of the above

 

13. If the number of threads needed for a project (width times sett) doesn’t match the twill repeat:
    1. Arriving at the match depends on the twill
    2. The number of repeats have to be increased
    3. The number of repeats have to be decreased
    4. Balancing threads have to be added

 

14. Which weft would show a bird’s eye twill best on a variegated warp of blue, green and purple?
    1. Blue
    2. Green
    3. Depends on the weft shade
    4. Variegated blue, green and purple

 

15. To weave a 1/3 and 3/1 straight twill on the same side of the fabric with 6 treadles, which combination will work?
    1. 1, 2, 3, 4, 1&3, 2&4
    2. 1&2, 2&3, 3&4, 4&1, 1&3, 2&4
    3. 1, 2, 3, 4, 1&2&3, 2&3&4
    4. None of the above

 

Answers coming up soon… next month, which is only a couple of weeks away!

Meanwhile here is a fun corkscrew twill scarf!

Happy weaving and stay safe and healthy!

          Please email comments and questions to This email address is being protected from spambots. You need JavaScript enabled to view it..

 

 

How Well Did You Know Your Twills? 

Marcy Petrini

September, 2020

Did you take the take the twill test in the August blog? If so, here are the answers. How well did you do? If not, you are still in time to take it, and then check your answers.

Here are the best answers.

 

Twill Test with Answers, Explained  

>

1. The minimum number of shafts needed for a twill is:
   1. 1
   2. 2
   3. 3
   4. 4

Answer: c. A 2/1 or 1/2 twill is an unbalanced twill on 3 shafts, one side is warp-dominant, the other weft-dominant; the twill is also called jean’s twill and it is, in fact, the fabric used to make blue jeans. You can also weave twills on 4 shafts, of course, but 3 is all you need; 2 shafts make plain weave and 1shaft? I am not sure what that is!

 

2. Floats in a twill fabric are:
   1. Weft floats
   2. Warp floats
   3. Both warp and weft floats
   4. Depends on the twill

Answer c. By definition a twill has floats, and a weft float means also a warp float; where the floats are depends on the twill, but both are present.

3. A standard tie-up is:
   1. 1&2; 2&3; 3&4; 4&1; 1&3; 2&4
   2. 4&1; 3&4; 2&3;1&2; 2&4; 1&3
   3. 1&3; 1&2; 2&3; 3&4; 4&1; 2&4
   4. All of the above

Answer: d. A standard tie-up on 4 shafts is the 6 combinations of all the shafts taken 2 at the time; but how we arrange those combinations on our treadles changes and should be maximized to weave as efficiently and comfortably as possible. Thus all the tie-ups listed here are possible. 

4. In an unbalanced twill:
   1. The fabric is warp-dominant
   2. The fabric is weft-dominant
   3. The fabric depends on the specific twill
   4. The fabric is warp-dominant on one side, weft-dominant on the other 

Answer d: When a fabric is unbalanced, it means the two sides are different, regardless of twill, one side is warp-dominant and the other weft-dominant; for example, a 1/3 twill. There are fabrics that are either warp-dominant on both sides of the fabric or weft-dominant on both sides of the fabric, but they are not unbalanced since both sides are the same.

5. Which cannot be woven on 4 shafts:
   1. Satin
   2. False-satin
   3. Broken twill
   4. Extended pointed twill

Answer: a. A satin requires a minimum of 5 shafts. False satin, broken twill and extended pointed twill can all be woven on 4 shafts. Usually a false satin is a 3/1 broken twill which resembles a satin.

6. Which are possible weaving combinations?
   1. Straight twill threading, pointed twill treadling
   2. Pointed twill threading, straight twill treadling
   3. Undulating threading, broken twill treadling
   4. All of the above

Answer: d. The wonderful thing about twills is that, in general, any threading can be woven with any treadling. All of those are all possible combinations.

7. A fancy twill is:
   1. An unbalanced twill
   2. An irregular twill
   3. A treadling method
   4. A twill with plain weave

Answer: b. A fancy twill is another name for an irregular twill, which is one that cannot be described by a ratio of warp and weft floats; regular twills can be described by ratios, for example, 2/2, 3/1, 1/2, on 4, 4 and 3 shafts respectively, meaning that the entire cloth is made up of floats with its specific ratio; an irregular twill can have a mixture of float lengths, and could include plain weave and could be unbalanced. A twill is a weave, whether it is regular or irregular, meaning that it has a threading and a treadling associated with it; a treadling method is a series of weaving steps without its own threading, but it can be applied to any number of threadings.

8. Waffle weave is
   1. A treadling method
   2. Pointed twill
   3. Bird’s eye twill
   4. Popcorn weave

Answer: a. Waffle weave is not a weave, it’s a treadling method. It’s a series of treadling steps applied usually to a pointed twill, since it doesn’t have a threading of its own. Both pointed twill and bird’s eye twill are twills and popcorn weave is not a weave, but another treadling method.

9. If the treadling step is 1&3, which is the “on opposite” treadling step?
   1. 1&2
   2. 2&4
   3. 2&3
   4. 3&4

Answer: b. “On opposite” treadling on 4 shafts is using those not in the original step. Thus, the shafts not used in the 1&3 treadling are 2&4. The other combinations listed all contain either shaft 1 or 3, thus they cannot be opposite.

10. Floating selvages:
    1. Should be used on the side where the weft doesn’t catch
    2. Should be used on both sides of the fabric
    3. Are not needed for twills
    4. Are needed for irregular twills

Answer: b. If a twill – or any structure for that matter – needs a floating selvage, both sides of the fabric should have them, even if it is only one side where the weft doesn’t catch the outer warp thread. Otherwise, the two edges will be different and even if the selvages will be hidden, for example in a garment or pillow, the take-up could be different so it’s best to use floating selvages on both sides. Some twills don’t require floating selvages and some irregular twill need them, but not all.

11. For a balanced fabric, the sett for a twill should be:
    1. About the same as for plain weave
    2. Slightly more open than a plain weave
    3. Slightly denser than for plain weave
    4. Depends on the twill

Answer c: The sett for any balanced twill is generally about 20% closer than the plain weave sett. A sett the same as plain weave or slightly more open would result in a fabric that is more weft-faced and thus not balanced. That may be desirable, but the question is about a balanced fabric.

12. For a weft faced twill, which of the following are true:
    1. The weft covers the warp
    2. The color interactions provide the pattern
    3. A number of different twills can be used
    4. All of the above

Answer: d. A weft-faced twill can be produced by a number of twills by opening the sett and letting the weft cover the warp completely on both sides of the fabric, which is generally sturdy, as in a rug. The motifs of the design are from the color interactions using at least two, but often more colors.

13. If the number of threads needed for a project (width times sett) doesn’t match the twill repeat:
    1. Arriving at the match depends on the twill
    2. The number of repeats have to be increased
    3. The number of repeats have to be decreased
    4. Balancing threads have to be added

Answer: a. Arriving at the exact match of number of threads in the project to twill repeats depends on the twill; the repeats may have to be increased (if the loom width allows), may have to be decreased and balancing threads may have to be added in either case.

14. Which weft would show a bird’s eye twill best on a variegated warp of blue, green and purple?
    1. Blue
    2. Green
    3. Depends on the weft shade
    4. Variegated blue, green and purple

Answer: c. If we want to see the twill, we need some contrast, so it depends on the shade of the weft; either blue or green may work, depending on shade. Variegated wefts on a variegated warp tend to obscure the pattern.

15. To weave a 1/3 and 3/1 straight twill on the same side of the fabric with 6 treadles, which combination will work?
    1. 1, 2, 3, 4, 1&3, 2&4
    2. 1&2, 2&3, 3&4, 4&1, 1&3, 2&4
    3. 1, 2, 3, 4, 1&2&3, 2&3&4
    4. None of the above

Answer: a. To weave the 1/3 twill, the 4 shafts need to be activated one at a time, so the treadles need to be tied to 1, 2, 3, and 4; to weave a 3/1 twill, 3 shafts have to be activated together: 1&2&3; 2&3&4; 3&4&1; 4&1&2; each of these combinations uses the odd vs. even pair, 1&3 and 2&4, plus another, which we already tied for the 1/3 twill; two feet are needed for the 3/1 twill portion of the fabric.

 

I hope you did well and that you learned something. Did you know that you can weave twill blocks on 4 shafts? It’s in the Pictionary. Here is the scarf.

 

 

Happy weaving and stay safe and healthy!

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Treadling: A Tale of Two Meanings

Marcy Petrini

Jujy, 2020

 The word “treadling” is used in one of two ways, which, unfortunately can cause a lot of confusion. These are the definitions:

1. Given a threading, treadling is the sequence of shafts activated (either raised or lowered depending on the loom) which produces the desired pattern or motif.
2. Treadling is the order in which treadles, tied to a specific tie-up, are used.

These two sound the same, but they aren’t. The treadling-as-a-sequence-of-shafts is independent of loom, meaning that if I give you that sequence, you can weave that pattern. Even if we switch raising and lowering shafts, the same fabric is produced, with the top and bottom on the loom reversed.

The second without its tie-up is ambiguous. And the treadling-as-the-order-of-treadles is meaningless for someone who weaves with a direct tie-up, for example a table loom, or with a dobby.

So, be cautions of your use. Several years back, a beginning student relocated, bought a table loom, and joined a guild in her new location. After having woven a few plain weave items, she decided to try a pattern. She asked a guild member what would be the next best thing. “A straight twill, said the guild mate, you thread it as in plain weave, 1, 2, 3, 4, and you also treadle it 1, 2, 3, 4.” And showed her a fabric like this:

 

 

  

My former student went home and wove this:

 

 

   

She used the drawdown below. She understood the treadling-as-a-sequence-of-shafts to be 1, 2, 3, 4.

 

 

  

Given that she had no other information, that’s a reasonable thing to conclude. What the guild mate meant, however, was treadling-as-the-order-of-treadles, shown below, which is generally for a floor loom.

 

 

 

 Furthermore, the guild mate assumed a “standard” tie-up, but that, too is confusing. The “standard” tie up on 4 shafts is all the possible combinations of shafts activated two at a time. There are 6 possible combinations. All of the tie-ups below would be considered “standard”, yet, for any treadling-as-a-sequence-of-shafts to produce a given pattern, each of these tie-ups would have different treadlings-as-the-order-of-treadles. How one ties those treadles to shafts at any given time and loom is a matter of preference and weave structure:

 

 

 

Back to my weaving student. If asked what is the treadling for the fabric my student wove, I would say:

  

1

2

3

4

Repeat

 

For the treadling of the fabric she wanted to weave I would say:

  

1 & 2

2 & 3

3 & 4

4 & 1

Repeat

 

Now my student could go to her table loom and weave it this way:

 

 

 

This drawdown is identical to the previous one with a 2/2 tie-up. My directions would be unambiguous.

 

Now let’s consider another common use. I am weaving a set of placemats, using a pointed twill; for each one, I will change the treadling without changing the tie-up, the tie-up without changing the treadling, and changing both the tie-up and treadling.

Here is my original pointed twill, tromp as writ:

 

 

 

Here are the treadlings:

 

 

as the order of treadles		as a sequence of shafts
1		1 & 2
2		2 & 3
3		3 & 4
4		4 & 1
3		3 & 4
2		2 & 3
Repeat		Repeat

  

For my next placemat, I am going to change the treadling to bird’s eye:

 

 

 Here are the treadlings:

 

 

as the order of treadles		as a sequence of shafts
1		1 & 2
2		2 & 3
3		3 & 4
4		4 & 1
1		1 & 2
4		4 & 1
3		3 & 4
2		2 & 3
Repeat		Repeat

   

 

Compare this drawdown with the previous one. The patterns are different as you would expect.

Now I am going to change the tie-up but use the same treadling as the original pointed twill: 

 

 

The drawdown is different than the tramp as writ, because, even though the treadling-as-the-order-of-treadles hasn’t changed, the treadling-as-a-sequence-of-shafts has:

 

Treadling-as-the-order-of-treadles

Original		New Tie-Up
1		1
2		2
3		3
4		4
3		3
2		2
Repeat		Repeat

 

Treadling-as-a-sequence-of-shafts

Original		New Tie-Up
1 & 2		1 & 2
2 & 3		3 & 4
3 & 4		1 & 3
4 & 1		2 & 4
3 & 4		1 & 3
2 & 3		3 & 4
Repeat		Repeat

  

So, when you use that terminology, saying that you changed the tie-up without changing the treadling, make sure that you – and your audience – understand that you are in fact changing the treadling-as-a-sequence-of-shafts, or the pattern wouldn’t change. And users may need the treadling-as-a-sequence-of-shafts because different weavers prefer different tie-ups, and some don’t use tie-ups at all.

 

If we change the tie-up and the treadling from the original pointed twill, we will change the pattern as expected:

 

 

 

The treadling-as-a-sequence-of-shafts now is below, even though the treadling-as-the-order-of-treadles has not changed from the bird’s eye treadling:

  

as the order of treadles		as a sequence of shafts
1		1 & 2
2		3 & 4
3		1 & 3
4		2 & 4
1		1 & 2
4		2 & 4
3		1 & 3
2		3 & 4
Repeat		Repeat

 

Here is another example where both the tie-up and the treadling were changed:

 

 

 

And we expect the drawdown to change… but it doesn’t!

 

 

That’s because the treadling-as-a-sequence-of-shafts hasn’t changed, it’s still:

 

as a sequence of shafts

1 & 2

2 & 3

3 & 4

4 & 1

3 & 4

2 & 3

Repeat

 

When I weave a pointed twill that has 6 steps in the treadling-as-the-order-of-treadles, I prefer my order of treadles to be straight, it makes my weaving faster than having to go back and forth with the conventional tie-up.

Next time you talk about a treadling, make sure that you are clear which use you mean - treadling-as-the-order-of-treadles or treadling-as-a-sequence-of-shafts – and if you hear someone talk about a treadling, determine which use of treadling is being discussed, and, if in doubt, ask.

 

Happy treadling!

 

 Happy Weaving!

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