Weaving Tutorial Part I: Preparing your project

Several of my very close friends are now weaving, and while they have the actual weaving part down, the prospect of calculating what they need for a project, prepping of the warp, and dressing of the loom may be a bit daunting.

There are a myriad of ways do each of these things, but I thought I would share how I do them, as a reference.

However, before I touch anything, I decide on a project and select my threads.

For this project, I will be making fabric for a poncho using 8/2 tencel for the warp and Noro Retro for the weft. The weft yarn is a single ply wool/silk Aran weight that I practically begged off a knitting friend, I loved it so. She graciously gave it to me, and the poncho is actually for her!


My finished dimensions for the fabric should be 200" x 33".

To figure out how much material I need, I use the Weaving Calculator at Weavolution.

There are a number of Warp and Weft Calculators. There are sheets you can print to do the calculations by hand and keep the sheets to make notes and refer to when doing future projects, I just happen to like the one above. As a knitter first, I use Ravelry to keep track of my projects and save extensive notes there.

Before tackle any of these calculators, particularly the one at Weavolution, you actually need to know a few things:
  1. The finished length of your project in inches;
  2. The quantity you intend to weave;
  3. Fringe length;
  4. Sample length;
  5. Loom waste;
  6. Takeup
  7. Length shrinkage;
  8. Finished width;
  9. Width shrinkage;
  10. Draw-in;
  11. Warp sett;
  12. Extra ends (floating selvage);
  13. Yards per pound.
Now, that sounds like a daunting list, it really does.

#1 -  The fabric I need to make a poncho needs to be 200" in length.

#2 - We only want to weave one poncho right now. 

#3 - No fringe, please.

#4 -  As we are planning to weave in evenweave, there is no need to sample; however, I usually add 4" for a fudge factor, particularly, as I use waste yarn in the beginning to close the gaps after I tie-on and to make sure my weft color choice is a good one. If I am using a pattern, I add more inches to sample because sometimes, my weft color is too close to the warp and my pattern is lost due to lack of contrast.

#5 -  Loom waste is a big one for me on the Macomber. I add 36". I don't know if this is because I leave long tails when I tie-on to the apron rod or my loom is just big, but a yard is a good number for me. Your mileage on your specific loom will vary. Experience is your friend on this one.

#6 - Takeup is the amount the warp thread drawn in as they are woven by the weft threads, i.e., the amount the the warp thread shrink in length as they are woven. I equate this to the vertical equivalent to Draw-in (#9 below). As Draw-in is easier to measure, I simply borrowed the number from the Draw-in (5%) and used it here. 

#7 - Length Shrinkage is how much the item shrinks once it is removed from the loom and is wet finished. Those are two separate things. When the threads are stretched under tension, they will be longer, than when they are relaxed. So, the second you cut them from the loom, they will be shorter. I have not found that Tencel shrinks much, if at all, when I wash it in cold. Thus, I do not loose much in length with washing, but I do when it is released from tension. As I am paranoid, I use the standard 10% to be on the safe side. (Caveat: If using cotton or a cotton blend, which shrinks A LOT, use 12% or more. If using cotton for the first time, you may wish to warp a small project of 3 or so yards. Keep good notes on the number of warp ends, width in reed, length on the loom, length prior to washing, length after washing, etc., to know exactly how much draw-in, takeup, shrinkage, etc. to be able to get accurate numbers for the next big project.)

#8 - Finished width is the desired width of the project - 33".

#9 - Width Shrinkage. In this instance, I am using a wool/silk blend. I expect some shrinkage as the wool will swell when washed. I think 10% is a bit much (based on experience), and will arbitrarily use 5%, as I expect the silk content will prevent it from shrinking too much. I am taking a risk here.  Again, if using cotton, expect quite a bit of shrinking. I have found most of my projects shrink more length-wise, rather than width-wise, I attribute this to keeping the tension of my warp much higher than the weft tension, as I weave.

#10 - Draw-in is the amount the warp thread drawn in as they are woven by the weft threads, i.e., the amount the the warp thread shrink in width as they are woven. The current project I have on the loom is 32" wide as it comes out of the reed; however, as it is woven and wraps around the cloth beam, it is 31" wide. Thus, my takeup is 4% on this project. As a rule of thumb, I typically use 5%, based on my experience.

#11 - Warp sett is dictated by the size (diameter) of the thread you are using. That sounds sufficiently vague, does it not?  It's really not that bad. Weaving threads are identified by their weight per pound. 8/2 thread is 3,360 yards per pound whether it is made of cotton, cotton and linen blended together, bamboo, wool, or Tencel. It is all identified as 8/2 thread.  

Here is a sett chart for common yarns. Note that the sett for 8/2 yarns of 3,360 yards per pounds is between 15-22 for tabby and 22-30 for twill. Tabby is another word for evenweave.

This means you can choose a warp sett between 15 and 22 for evenweave using 8/2 thread for warp. 

What sett you use also depends on the size reed you have. If you have a 10-dent reed, you may be more inclined to use a sett of 20 (pulling two threads through each slot in the reed). If you have a 12-dent reed, you may be more accustomed to using a sett of 24 (again pulling two threads through each slot in the reed).

However, using a Reed Size/Sett Substitution Chart, you can maximize your reeds to accommodate just about any sett you like. As there is an explanation and example in this .pdf, I won't go into an explanation, but if anyone has any questions, just let me know.

As with most things, doing a sample and experimenting with different warps and wefts at different setts will give you an idea of the different type of fabrics you can make. For tea towels out of 8/2 cotton, I have been very happy with warp setts of 20, 22, and 24. For poncho fabric using 8/2 tencel and fingering and sport weight weft, I have used sett a set of 24 and 22, respectively.  

As the Aran weft is significantly thicker than the fingering and sport weight, I am debating whether I should use a sett of 18 because I do not want the fabric to be too dense. My goal is do have some weight to it, but for it still be somewhat drapey. Using a 12 dent reed, the Size/Sett Substitution Chart directs I will sley the reed as follows: 1 thread in a slot followed by 2 threads in a slot, repeat.

#12 - Extra threads. Floating selvages tend to trigger very animated debates among weavers. I am in the pro-FS (floating selvage) camp and use them for all my weaving. Period. I like them and use them because I like consistency and find great comfort in doing things the same way, every.single.time. I happen to think they are crucial when doing patterns, particularly twill to give nice, even edges. I understand they are not necessary when doing evenweave, but I use them anyway because it is what I do. I respect the individual weaver's choice to use or not use FS, as desired. 

#13 - Yards per pound. In this instance, yards per pound is easy. 8/2 Tencel from Valley is 3,360 yards per pound because it says it is. 

Once all of the above information is input into the weaving calculation, this in the information given:

Warp Calculation:

Warp length is 274 inches (7.6 yards)

Length to weave each article is:
230 inches (under tension)
220 inches (relaxed)

Width in reed is: 36.3 inches
Number of warp ends: 655

Total Warp Required: 4978.0 yards (23.7 ozs.)

A little bit more information is required for the Weft Calculation:
  1. Picks per inch (PPI);
  2. Takeup; and
  3. Yards per pound
#1 - PPI is picks per inch of weft threads, which are very much like the ends per inch of the warp threads. The most exact way of measuring this is to count the threads of actual woven fabric, but that assumes the fabric is already woven. As we are planning a project, the next best way is to count wrap the thread around a ruler and count how many wraps there are in an inch.

If you are like me and coming to weaving with a knitting background, here is a quick chart that translates lace, fingering, sport, worsted, etc., yarn into wraps per inch (wpi) to help determine warp sett.

This chart is just a guideline. While the quick chart above tells you that there are 12 wraps per inch of worsted weight yarn, it does not tell you what the sett for worsted weight yarn is, unless you read the little paragraph below it that says: "To guesstimate a weaving sett from wraps-per-inch, divide the wraps-per-inch by two to get an approximate sett for plain weave."

Yeah. That one.

I missed it the first time time and ordered twice as much yarn as I need for a project...

For my poncho project, I actually have Aran weight yarn that is not listed in this quick chart. So, I took out my handy-dandy ruler and actually loosely wrapped the yarn around it for an inch. I got 10 wraps per inch, which gave me a PPI of 5.

#2 - Takeup - again. We may be double-dipping here, but for the same reasons that I used above, I am using 5%.

#3 - Yards per pound.  One of the reasons I went to law school is that Math was not my best subject; however, in my craft life, I find I spend an inordinate amount of time doing math. Moreover, I find I enjoy doing math. Whoa.

Sincerely. 

It was a shock to my system, as well.

In any event, with a significant knitting stash when I began weaving, I found I had to learn how to convert fingering weight yarn into something a weaving calculator would recognize and that something was based on yards per pound. 

One skein of this Noro Retro weighs 50 grams and 100 meters long. Note, that it is neither in pounds nor yards.  However, Googles tells me that 1 pounds is equal to 454.592 grams. I am rounding that up to 1 pound = 454 grams.  Also, 100 meters = 109.361 yards. 

To solve for Z (which is yards per pound) my mathematical equation will look like this:

109.361 yards/50 grams   x   Z/454 grams

The first part of that equation is the original 100 meters/50 grams with the meters converted to yards.  I am using 454 grams in the second part of the equation, as 454 grams is the same thing as 1 pound.

To execute the equation I will cross multiply 109.361 x 454 = 49,649.894, which I will then divide by 50 to get 992.99788 or 993 yards per pound.

So, my Aran weight yarn is 993 yards per pound. I hope that makes sense.

When I add those numbers to the Weft Calculation, I get:

Total Weft required is 1164.6 yards (18.8 ozs).

That is awesome, because I have a total of 16 skeins of the Noro Retro for a total of 1,760 yards!!

According to this, I have enough to make a poncho for my friend! YAY!

Next time, we will prepare the warp using a warping mill!

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