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Satins and Sateens (Part 2)

Marcy Petrini

June, 2017 

Last month we talked about how to obtain steps to derive the threading for a satin; while we call satin the warp-dominant side of the cloth, and sateen the weft-dominant side on the other face of the fabric, the term satin is generally used to describe this structure.

In the May blog we also applied the rules to a 5-shaft straight draw, which gave us possible steps of 2 and 3, and we saw why it is not possible to have a true satin on 6-shafts. But, with an 8-shaft loom, it is possible to weave 7-shaft and 8-shaft satins. Here is how:

 

Rules

Example for 7-shaft satin

Example for 8-shaft satin

Start with a straight draw for n number of shafts, with n at least 5

1, 2, 3, 4, 5, 6, 7

1, 2, 3, 4, 5, 6, 7, 8

Do not use a step number of n because it wouldn’t allow any threading

Step cannot be 7

Step cannot be 8

Do not use a step number of 1 or (n - 1) since it wouldn’t change the straight draw

Step cannot be 1 or 6

Step cannot be 1 or 7

The step number cannot have a common factor (mathematically) with n

2, 3, 4, and 5 do not have a common factor with 7

2, 4, 6 are or have common factors with 8

The remaining integers can be used as steps

Step of 2, 3, 4, and 5 are possible steps

Step of 3 and 5 are possible steps

 

Compare the drawdowns below of a 5-shaft satin (blue warp, green weft), also shown in last month blog, with the 8-shaft satin (red warp, gold weft), both with a step of 3; the sateen side is first, followed by the satin side:

 

Click here for the full-sized draft (a PDF will open in a new window).


Click here for the full-sized draft (a PDF will open in a new window).

 

The floats on a satin are always one thread less than the number of shafts used; thus, a 5-shaft satin has floats that are 4-thread long while an 8-shaft satin has floats that are 7-thread long. Whether the floats are too long depends on the sett, which in turn is related to the size of the thread, but generally it means that thin threads are best; in order to have the two sides show more of the weft or of the warp, we set the warp more closely than we may for a balanced twill. For example for a silk blend with a plain weave sett of 60 epi, the calculated setts for a balanced will, a 5-shaft satin and an 8-shaft satin are 80, 86 and 96 epi respectively.

It is possible to weave a satin by threading a straight draw and obtaining the treadling by applying the step to the tie-up. Here is a comparison of two 5-shaft satins (sateen side), using a step of 2; the black warp is identical to the one we saw last month, the pink warp is threaded as a straight draw, with the steps shown in the tie up. When a straight draw is treadled as a straight draw, a 1 / 4 straight twill appear; when a satin threading is treadled as a satin, a 1 / 4 straight twill also appears.

 

Click here for the full-sized draft (a PDF will open in a new window).

 

You can see that the structures of the two satins are the same. So, apply the step to the threading or to the tie-up / treadling depending on your preference.

In the last blog we also said that a satin is not possible on four shafts. Applying the same step rules to 4 shafts, we see why we need at least 5 shafts to weave a satin:

 

Rules

No 4-shaft satin

Start with a straight draw for n number of shafts

1, 2, 3, 4

Do not use a step number of n because it wouldn’t allow any threading

Step cannot be 4

Do not use a step number of 1 or (n - 1) since it wouldn’t change the straight draw

Step cannot be 1 or 3

The step number cannot have a common factor (mathematically) with n

2 is a factor of 4

The remaining integers can be used as steps

No possible steps left!

 

However, with 4 shafts we can weave a false satin, a 1/3 broken twill. As in the satin, we usually weave the weft-dominant side up; also as in a satin, we can break the twill either in the threading or in the treadling. Compare the drawdown of the 1/3 broken twills with the 5-shaft satins of the previous drawdown. On 4 shafts, more warp shows on the weft-dominant side and more weft shows on the warp-dominant side; but the effect is similar. The 4-shaft 1/3 broken twill has also the advantage of having shorter floats, 3, rather than 4 in the 5-shaft satin.


Click here for the full-sized draft (a PDF will open in a new window).

And here are the fabrics; the weft-dominant and the warp-dominant sides of the 1/3 broken twill:


 

The top of the scarf below, shown on the left, is weft-dominant, but there are also warp-dominant satin blocks; conversely, the right side, the bottom, is warp-dominant but with weft-dominant sateen blocks. When we combine satin blocks in this way we obtain damask; similarly, combining false satin blocks produces false damask. That will be the topic of my next blog.


 

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