Marcy Petrini 

March, 2025 

I have just finished teaching a MAFA zoom class on tied unit weaves to a wonderful group of weavers, so I have been thinking some more about tabbies.

In the February blog, we discussed how tabby can refer to the ground cloth of a supplementary weft structure. As I mentioned, on four shafts, the tabby treadling for overshot is 1 & 3 vs. 2 & 4, odd vs. even; for summer and winter, a tied unit weave, the tabby treadling is 1 & 2 vs. 3 & 4, or tie shafts vs. all pattern shafts. Thus, on eight shafts the treadling for the background tabby of summer and winter becomes: 1 & 2 vs. 3 & 4 & 5 & 6 & 7 & 8.

I kept that rule in mind as I studied other tied unit weaves. The rule applies to some, for example it applies to the single, three unpaired ties, 1:1 ratio, called “Half Satin”, shown below (all drawdowns are sinking shed).

The tied unit weave structure called “Tied Latvian” (double two paired ties with 1:2 ratio), however, uses the odd vs. even treadling as shown below:

There are many variations for treadling the background among tied unit weaves. One example is “3:1 Beiderwand“ which is a double, two unpaired ties structure, with a 1:3 ratio and the pattern shafts organized in reverse pointed twill order with the ties. As a result of this interesting arrangement, the tabby ground is formed by treadling the pattern ties plus the odd pattern shafts vs. the even pattern shafts as shown below.

One day I was ready to weave “2:1 Beiderwand”, a double, two unpaired ties with a 1:2 ratio. I always weave a background tabby header to start, to double check threading and sleying. This tabby ground, however, was not weaving correctly. After checking my threading and tie-up several times, I went back to the drawdown: and there it was! A true tabby cannot be woven across the fabric as we can see from the drawdown below.

Plain weave is formed underneath the blocks on both sides, but not across the fabric.

I should have used the sure way to determine whether any threading will produce plain weave across the fabric. Set up two lines, treadle 1 and treadle 2. Alternate the threads in the threading in the two treadles. For example, block A of “2:1 Beiderwand” from the drawdown above is: 1, 3, 4, 2, 3, 4. We alternate these six threads:

Treadle 1: 1, 4, 3

Treadle 2: 3, 2, 4

We don’t have to go past the first block to realize that weaving a tabby across the fabric is impossible as shafts 3 and 4 appear in both treadles. Those two shafts will stay up or down with every tabby pick preventing interlacement.

I have used this method for complex twills, for example. I was just lulled into a false sense of security that all tied unit weaves were following the rules.

Happy Weaving!

Marcy