Fiber Study

Updated 9/21/19

My goal as I breed my Pygoras is to create a serious fiber producing breed that can become a viable option in the fiber community, and a serious component in the fiber industry. I feel that the best way to get the highest production from each animal, as well as produce the highest quality product is to breed for excellent separation of guard hair from fiber. This article (pdf file below) is the beginning of my research into good separation of guard hair, and I hope to continue learning about it more in the future.

What is Required for a Serious Commercial Pygora Fleece

Pygora is already recognized in the fiber world, but it just needs more credibility. To come to an understanding of what is required for Pygora fleeces to be taken seriously by fiber purchasers, we need to understand exactly what fiber enthusiasts and potential commercial buyers are looking for, especially in regards to Pygora.

To find more information on this, I went to Terry Mattison. Terry is a long time retailer of Pygora fiber who retired recently from her Pygora business. Over the last 15 years, she has attended fiber festivals all over the US selling her hand dyed Pygora and Pygora blends. She processed approximately 50-100 pounds of pygora fiber each year, so has evaluated pounds and pounds of Pygoras fleece over the life of her business. After processing that much raw fleece, she also knows what type of fleece comes back with a good or bad result from the mill. In addition, she has talked to countless fiber enthusiasts, spinners, weavers, and felters over the years and has a very good understanding of what they are looking for.

Terry will tell you that without a doubt that if people are looking for Pygora, they are looking for Type B. This is not surprising since it is the fiber that is unique to Pygora. They want the softness, warmth, luster, drape, and great staple length that make Type B fiber so unique among fiber types, and so unique to Pygora. 

When I was the PR Chair for the PBA some years back, I put in a call to Wild Fibers Magazine (an amazing fiber magazine that is only published annually now) to find out about placing an ad for PBA. I was surprised when the editor, Linda Cortright, picked it up the phone, and said, “Oh I had to talk to you because last week I met with the head of the largest cashmere processing company in Europe. During our conversation he actually told me that he wished Pygora was more available! He said it is so much easier to work with then cashmere, and he would love to have more!” Wow! I told her how wonderful for her to share that with me, and asked if I could get his contact info for a formal quote. (Not surprisingly, she was not comfortable giving that information out. And probably he wouldn’t have talked to little old me anyway!) Because of Type B’s similarity with cashmere but its superior length, it has the potential to become a much sought after fiber.

On the opposite end of the spectrum, when I was recently talking to the lady at Yocom-McColl (a company that does micron testing on fiber) and asking some questions about the test results, one of her off hand comment was “ Well, Pygoras don’t produce good fleece anyway because there is no consistency.” This is, unfortunately, is a common feeling among the fiber community. This is because of the wide array of fiber from Pygoras that is being sold, all different fiber types that may not be described well, and...fleeces that may not have all the guard hair processed out.

That leads us to the next important component, separation of guard hair.

Good Separation of Guard Hair for Higher Harvest

Have you ever sent your fleece to the mill, waited expectantly, and then when it comes back, you think, “Wait, what did I just pay for? There is still tons of guard hair in this!” It may or may not be the mills fault. If the mill has sent your fleece through numerous passes on the dehairing machine and what you get back is still prickly and full of guard hair, it could be there is not enough difference between guard hair and fiber for the machine to separate it well.

A dehairing machine does its job based on the difference in the diameters (measured in microns) of the individual hairs, which translates into the stiffness or softness of each hair. The stiff, prickly guard hairs stick out of the soft fiber as they go over a roller on a carding cloth and are picked up by an opposing carding cloth roller, while the softer fibers stay on the original carding cloth thus separating the two. If there isn’t much difference between the guard hairs and the fiber, the prickly hairs will not be distinct from the fiber, and no matter how many passes the fiber goes through, you won’t have good dehairing. Also with bad separation, there will be a loss of good fiber because the opposing drum wants to pick something up and will take the good if it can’t find the bad. So you loss on two counts. Final product with guard hair still in it, and loss of good fiber that should have been saved. Terry Mattison verifies well dehaired fiber is what everyone is looking for. 

How Do You Know if There is Good Separation in Your Fleece?

So how do we really know if we have a fleece with good separation or not? What is the best way to evaluate this? We need to be able to make good evaluations of our fleeces, not only for which ones

will be worth sending to the processor (don’t spend the money if the fleece will come back full of guard hair!) but also in our breeding decisions for future fleece production. Let’s look at several ways to evaluate that.

Prickle test. A well dehaired fleece is a good indication of good separation. If you ever wonder how well dehaired your fiber is, you can do a prickle test against your skin. Take a small sample of your dehaired fiber (just a pinch will usually do) and put it somewhere on your person where it will “rub” for a few minutes. For instance, put a little tuft under the band of your watch, or in the waistband of your jeans, or some ladies will stick a little tuft in the corner of their bra. Leave it there for a few minutes as you move around. Is it itchy? This is a good way to know if most of the guard hairs are removed from a fleece. Also remember that everyone is different! Some will have more sensitive skin then others, so what works well for one, may not be for another!

Color board for visual analysis. This is a tool that judges often use in the show ring to analyze a fiber sample. It can be a great help to everyone who wants a closer look at some fiber. This tool is pretty simple – go buy some black, bright blue or red felt or colored paper (I like the bright blue). Place a small sample of fleece that has been plucked from middle of the barrel of the goat or pulled from a shorn fleece (hopefully from close to the middle of the barrel). Spread it thinly on the color board, and just take a gander. Can you see the guard hairs? If you have a fleece with excellent separation, you can see the difference between the guard hairs and fiber. I actually like to use a magnifying glass and very bright light to get a really good look.

Hand process to investigate separation. Another way to evaluate your fleeces is to use hand combs to manually separate fiber from guard hairs. This takes a little practice and a demonstration is helpful, but basically by combing a handful of the fleece back and forth between the two combs (make sure they are for fine fiber), you can separate the good fiber from the guard hairs. Is your sample easy to separate? Do you find that when you’re done there isn’t much usuable fiber left at all? Or do you find that you had an easy time getting that lovely soft fiber away from that guard hair?

Number of Dehairing Passes. When you send your fleeces out for processing, most processors will indicate how many passes the fleece went through. If you are confident in your fiber processor, the number of times they deem necessary to put the fiber through can indicate how easily it is dehairing. If you have fiber that came back with hardly any guard hair, and had fewer passes than other fleeces, this is a good indication of distinct separation of guard hair. If you have fleeces that go through lots passes and still have guard hair or seem scratchy, could be they don’t have distinct separation.

Micron Testing. Ok everyone, this is the really interesting part to me! Utilizing micron count test results I think could be an excellent tool for us in understanding our fiber. This is an area that I think could use more research into what kind of a tool it could turn into for Pygora people when evaluating fleeces.

My interest in this tool started when a small group of PBA folks gathered at Erica Browns house last fall to take a class held by Terry Mattison on fiber separation. This class was focused on evaluating pygora fleeces that will process well and have good yield, meaning they have good separation of guard hair. I brought several fleeces to this class that I had micron tested. I brought those results and enough fleece for each of us to take a close look at a sample of each. After learning the basic technique of combing to separate fiber from guard hair, each participant was given several fleeces

to separate that were from my tested fleeces. Everyone evaluated each fleece and chose which fleeces they felt had good separation. We then looked at the correlating micron test reports to see if we could see what the information on the reports might tell us about the fleeces we felt had better separation. I would like to stress that we only looked at 4-5 samples so this is a very limited overview.

Each of my fleeces had been tested twice. The FIRST set of test results for each fleece EXCLUDED fibers over 30 micron, which basically means it EXCLUDED GUARD HAIR. Excluding over 30 micron count fibers is done to give us a more accurate micron number on the fiber that you will actually use. (more on this below).

The SECOND SET of test results didn’t exclude anything, but included all hair/fiber from the sample, meaning it INCLUDED GUARD HAIR (no micron cut off at all). This is potentially the more interesting test information when we are looking at guard hair in relation to the fiber. It is a COMPLETE LOOK AT THE WHOLE FLEECE.

My testing was done by Yocom-McCall. I spoke with Angus at Yocom McCall to try to get a better understanding of the data that was included on the test results. We had a little trouble understanding one another initially because generally he talks to people looking for consistency, and I was actually looking for inconsistency (guard hair distinctly different than fiber). However, I did come away with some information that was helpful. The numbers on the report that are the most applicable to this topic are the Mean Fiber Diameter, Standard Deviation, Coefficient Variation, Percentage of Fiber over 30 Micron, and last but not least, the histogram graph - the graph being particularly helpful. I have samples of micron report shown below.

Just to be clear, if you are not familiar with micron testing, low micron numbers indicate fine fiber, high micron numbers indicate coarse fiber. Fine wool is less than 21, medium wool is 22-29, coarse wool is 30-34, and very coarse is 36+. Cashmere is anything 19.5 microns and lower. Kid mohair is 23-30 microns, and adult mohair is 31-43+. Notice that the “coarse” category starts around 30 microns for all of these. In the fiber industry, 30 microns is a generally accepted number for when the “prickle” factor occurs, or in other words when the fiber will start to feel itchy and scratchy. For Pygora, we generally measure our fiber with a cut off at 30 microns, using the industry standard for what should be deemed guard hair, although our guard hair could be less than the 30 microns. Excluding over 30 should give us a more accurate number for the fiber that will actually be used once it is dehaired. Pygora generally ranges from 16-23 microns for the usuable fiber when over 30 is excluded.

I will try to explain what all the different measurements are that are given on the fiber test report. However, I am not a math whiz, so there may be others out there who could explain this better!

Here is a sample of a micron test. We will look at individual ones more closely later. This one contains ALL fiber (no cut off at 30).

Mean Fiber Diameter basically is the
average fiber diameter. Add up all the
micron values from all individual fibers
and then divide by the number of
individual fibers that were measured. If
you are looking at the entire fleece, and
the Mean Fiber Diameter is low, it
means that in general all fibers
(including guard hair) are finer. If the
number is higher, it could mean that in
general all the fibers are coarser OR it
could mean that you have lots of very
fine fiber, AND lots of nice distinctly course guard hair, and there is a wide dispersal of fiber diameters. When including all fibers, the mean is a very general number, but could be helpful in conjunction with other information. The histogram can be very helpful for understanding what this number is saying.

This number is very helpful and important, however, if looking at results that cut off at 30 micron. Then it will give you a very good indication of the fineness of the fiber you will be selling or using.

The Standard Deviation (SD) definition is “a measure that is used to show the amount of variation in a set of numbers.” A low SD indicates that the data tends to be close to the average of the set, meaning there isn’t a lot of variation. If you are cutting off the test at 30 micron to exclude the guard hair, a low number is good, because it shows there is good consistency in the usable fiber. For instance if all the fibers measure 19 to 21 microns, your mean (or average) will be 20 and you will have a low SD because they are close together. But if you have fibers all the way from 16 to 24, your average will still be 20, but your SD will be high because there is lots of variation. This number gives you an idea of how constant your sample is.

In our situation, if you are including ALL fibers, a higher SD might indicate that there is good definition of the guard hair because you want “less consistency.” You WANT there to be a big difference between fiber and guard hair. However, again to understand if this number is telling you what you want, you need to have it clarified by looking at the histogram. It could mean the fleece is a jumble of all different micron sizes, and it won’t separate well at all, or that you have two distinct set of fiber that are far from each other, therefore you will have good seperation. More on this below when we talk about the samples.

The Histogram is really where its at for understanding a fleeces separation. It gives you a visual look at the actual make up of the fiber measurements and how they relate to each other. It is VERY helpful for analysis. If you are looking at a test that had a cutoff at 30 microns (so no guard hair), you would generally want it to be a nice, steep bell shape (rise swiftly up, small peak, swiftly down). This would mean that the most of the fibers are all pretty close to the same diameter, nice and consistent.

However, with a full fiber sample (no cut off), I believe what we are looking for is a histogram with two distinctive peaks, although the second “peak” is not so much a peak as a low, long plateau. One peak would represent the good, usable fiber, and the other the guard hair.

(It should be noted that on my examples, I should have stated a cut off number that was the same for all samples so that my histograms would look visually consistent. If you will notice some of these graphs go to 60 micron maximum and some go over 100 micron depending on what was in the fleece. This makes the histograms unequal visually since some are representing 0-100 microns and some are for 0-60, so bells that could be very similar between goats look quite different.)

The Coefficient of Variation is the Standard Deviation divided by the Mean (or average). I still am not sure if this is a valuable number or not, but a higher Coefficient of Variation does seem to indicate better definition of guard hair, or at least a higher level of micron diversity. Whether that is good diversity (two distinct peaks) or bad diversity (a flat bell) again would have to be determined by the histogram, so this number might not be that helpful. However, I think it could warrant more study.

Fibers Greater Than 30 Microns is a pretty straightforward number and is definitely valuable information. If you have good definition of guard hair, but a high percentage of guard hair, it is still not a very productive fleece. On the opposite side, if there is good definition guard hair, and a low percentage of guard hair, that is an excellent fleece. This number tells you about how much loss there will be in a fleece once dehaired. 

Samples and Histograms

Below are photos and histogram of four different fleeces, each with comments and comparisons. (I apologize for the bad photos. Only had my iPhone for photos!) One thing to note as we review this is that I think what we want in the histograms is two very distinct peaks that would represent a very distinct fiber and very distinct guard hair.

W Fleece

The first fleece is from goat W, and is actually a Type C fleece. However this goat had Type B characteristics in that she never shed. I sheared her once a year and was able to get a lovely 3-inch staple length of very fine fiber. I feel that the strong guard hair may have helped keep her from matting. The draw back is that I only was able to get one shearing from her a year rather than two, so a true Type B would be superior to this fleece by having two shearing a year. I wanted to use this sample because it has excellent separation of guard hair that is easy to see with the naked eye.

It should be noted that W’s guard hair is VERY high micron count, higher than usual. On her histogram, you see it shows up as a very small peak way over in the 60-80s range. If you look at the <30 histogram she has a lovely bell shape on the useable fiber and her average is 16 microns.

J & L Fleeces

J and L fleeces are both strong Type B fleeces and seem to have pretty good separation of guard hair. I’ve included both because one is grey and one is white, and identifying guard hair can be harder in white fleece. They are really quite similar in many other ways. First we’ll talk about J.

These fleeces are interesting in that you will note that they both have two very distinct peaks in their histograms, which should indicate good separation, but the second peak is still fiber that is less than 30 microns. So is it actually guard hair? Or silky guard hair? Based on the industry standard, these fibers in the second peak would not be considered “prickly” since they are under the 30 mark, but how would they actually feel? More on this later with the dehaired micron test results.

It should be noted that J was the favorite in

our combing class for separation (L was not included in the class so no comparison). J also only had 4 passes through the dehairing machine

when I had it process versus 4-5 for other fleeces, so the processor also felt it was a little easier to dehair. However, in the processed fleece that I received back, I can still see some hairs that appear thicker then the fiber. The question would be if these silky guard hairs are going to be undesirable or not.

Also, it is interesting to see that in the all-fiber data, this fleece only had 5.6% above 30 micron. This should mean is it almost all useable fiber if you decide silky guard hairs are not a problem. That data can be good information on the productivity of the fleece.

In L fleece, it is also easy to see the guard hairs (even though the guard hairs are not a contrasting color which is common in the black/grey fleeces).

This is another fleece that only went through the dehairer 4 times versus more for others. But it shows in the histogram that the two peaks are under 30 micron like the other Type B fleece so, again, bares more research on if this is a good trait or not. There is also a small peak at 50-52 so this is probably the real guard hair.

S Fleece

This fleece from goat S does not have strong definition between fleece and guard hair, but rather a whole gamet of diameters in the fibers. The arrows show that there are distinct guard hairs (black arrow), but also silky guard hairs (red arrow) and then the actually fiber (green arrow). This fleece has strong A Type characteristics.

You can see in the all-fiber histogram that it is a flat bell shape, with only a hint of two peaks. This means there are about equal parts of many different fiber diameters, which could cause a problem for the dehairing machine. There are also a lot of fibers over 30 microns. This fleece leans pretty heavily towards “mohair-like” and may not dehair well.

What surprises me on this fleece is that it says the SD is only 11.2 microns. And the coefficient is also low even though we can see in the histogram that he has a wide variety of fiber diameters. So either there

was a computational error, or I am still not understanding these calculations quite right!

I did send in several dehaired samples for micron testing to see if we could learn anything by comparing the original all-fiber results with the dehaired results. Here’s what I found:

Goat D Dehaired

This goat is not mentioned in the above samples but I thought it was good include her results because they seem to really be what we are looking for. You will notice that the dehaired results are very similar to the all-fiber results in shape of the. Her mean fiber diameter in her original test with a 30-cut-off was 19.8 micron (those lab results not shown here), and the Mean after dehaired was 20.0 – so pretty close! I believe this indicates this was a fleece that dehairs well!

Goat J

D - All Fiber

D - Dehaired

The thing I found interesting in Goat J’s result is that the shape of the histogram did change in this result. It originally had two peaks that were both under 30. I wondered how this would interpret in the dehairing process. What happened is we lost a lot of the very fine fiber in this dehairing if you look at the numbers below the peaks. So this means we are losing good fiber. Her original test for less-than-30 showed an average of 16.9, but after dehairing it is 20.1 micron. Hmmm, very interesting. Next time I will also pay attention to how much weight was lost, and it may indicate how much really good fleece we are losing.

J - Dehaired

Goat S

This is the goat above that had three very distinct types of guard hairs. It is very interesting to note there is also a non-distinct peak in the dehaired results, so his original histogram definitely did indicate that the machine would have a hard time dehairing efficiently. His cut-off-at-30 average was 23.4 and the actual average after dehairing was 24.5. Close but not as close as Goat D above.

S - Dehaired

My observations here are obviously based on an extremely small sampling, but I think it would be so very interesting to do more in depth study to gage how the micron test data can help us. These reports could potentially be a great guide to help us evaluate fleeces both for production purposes and when selecting breeding stock to help solidify good traits in Pygoras. It could also help people who buy animals from a distance and can’t see them up close.

In Conclusion

In conclusion, I hope that this has presented some interesting and motivating information for serious pygora breeders out there who want to see the breed claim a permanent spot in the fiber world. I feel Pygora fiber, if it has good separation so it can be dehaired well, is an amazing addition to the fiber industry and can demand a permanent place there. I personally will be planning to breed for good separation, and hope that there are others who will do the same. Hopefully after some years of focused breeding, there will be Pygoras out there consistently producing incredible, prickle-free fiber that will stun and thrill the fiber world. 

© Kari Schroeder 2013