Understanding the Shadow Weave Tie-ups
Why Change Tie-Ups?
Although it is usual to weave shadow weave with the standard Atwater or Powell tie-ups, it might be more comfortable to work with a different arrangement. For example, some weavers like to treadle from left to right, while others prefer an alternating sequence. Once we understand the relationship between the shadow weave tie-up pairs and the threading pairs, we can rearrange our tie-ups as we wish.
A Question of Blocks
The key to understanding the tie-ups is to know which shadow weave "blocks" - i.e., which harness pairs - should weave together. The blocks that weave together are tied up to a pair of treadles: one is connected to all the primary (Dark) harnesses and the other to the shadow (Light) harnesses. Here's an example, for four harnesses, using the Atwaterthreading system:
Let's call our first threading pair (1D, 3L) block A.
Our second threading pair (2D, 4L) will be block B.
Our third threading pair (3D, 1L) will be block C.
Our fourth threading pair (4D, 2L) will be block D.
In shadow weave, adjacent blocks weave together. If there are four possible blocks (A, B, C, D) then they weave together in groups of two: A and B, B and C, C and D, D and A.
What does that mean?
Weaving A and B together:
A = 1 (primary) and 3 (shadow); B = 2 (primary) and 4 (shadow). To weave these two blocks together, you need one treadle tied up to the primary harnesses (1 and 2), and one to the opposite, shadow harnesses (3 and 4).
When you step on the treadle that lifts 1 and 2, you weave the dark picks of blocks A and B together, and then when you treadle 3 and 4, you weave the light picks of blocks A and B together. Alternating these two treadles repeats the dark/light horizontal lines.
You can arrange them like this, or you can arrange them to
alternating and treadling as drawn in, treadle left to right, if you want.
which is how Atwater does it.
Weaving B and C together:
To weave B and C together we join B = 2 (primary) and 4 (shadow) with C = 3 (primary) and 1 (shadow). These two blocks together need two more treadles: one tied up to the primary harnesses 2 and 3, and one to the shadow harnesses 4 and 1:
Atwater tie-up (as drawn-in) left-to-right
Weaving C and D
To weave block C (3 primary, 1 shadow) and D (4 primary and 2 shadow) together, we need one treadle to lift the primaries (3 and 4), and one to list the shadows (1 and 2). We already have them! We just need to treadle them in the opposite order from when we wove A and B together:
Atwater our alternative.
Weaving D and A - the last sequence
Block D (4 primary, 2 shadow) weave with A (1 primary 3 shadow), so we need treadles to lift primaries 4 and 1 and shadows 2 and 3. We have those already also, and just treadle them in reverse order:
Atwater our alternate
More than Four?
The number of blocks that weave together is the number of threading blocks used in your pattern, divided by two.
We saw that our four block pattern (ABCD) wove two blocks at a time: AB, BC, CD, DA.
Each treadle was tied to 2 harnesses.
So, for a six-block pattern (ABCDEF), you weave three blocks at a time: ABC, BCD, CDE, DEF, EFA, FAB. This means each treadle is tied to 3 harnesses.
For an eight-block pattern (ABCDEFGH) you weave four blocks at a time: ABCD, BCDE, CDEF, DEFG, EFGH, FGHA, GHAB, HABC. Each treadle is tied to 4 harnesses.
On the following pagesare charts that show the treadles needed for the Atwater and Powell methods, for 4, 6, and 8 harness designs.
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