Tuesday, December 4, 2007

Who Spotted the Threading Errors?

When I looked at the pictures I had taken of this first 8-blocks crackle sampling, one thing immediately jumped at me. Something I had not noticed in the weaving. Something I had not noticed in the computer drawdown. Here it is, with the black arrows pointing to the problems that caught my attention:



Those arrows point to places where the weft yarn skips over more warp ends than it ought to. I went back and looked at the computer drawdown. These skips are not there. Clearly I made a mistake in the actual threading. When I looked at my threading and my notes, however, I threaded exactly as I had printed the threading out. However......and this is a big however....

The error appears at the point where I end the last block of the repeated group of blocks and begin the first block of that group of blocks. And since I repeated the group of blocks three times, that error occurs two times.

Here is the threading for the end of the repeat:

4 1 4 2

Here is the threading for the beginning of the repeat:

3 1 4 1

It had looked to me like there would not be a problem here when I entered the threading blocks into my computer software. What I did not do, however, is write out the last block and the first block as they would appear together. And this is what I would have gotten, had bothered to do this instead of thinking I "knew it all:"

3 1 4 1 4 1 4 2

Now the error is obvious to me. There is a repetition of the 4 1 pair. That repetition destroys the crackle block structure at the point and results in an extra bit of weft going over the warp ends. To correct the matter, all I have to do is leave out two warp ends, one on 4 and one on 1. Doing that gives me:

3 1 4 1 4 2

The first four numbers (3 1 4 1) give me one unit of the first block. The second two numbers give me the last two threads of the last block. The entire unit of that block reads 1 4 2 4. So, the last unit of the last block and the first unit of the first block, when written out look like this:

3 1 4 1 / 4 2 4 1

The slash indicates the division between the two blocks. All is well.

Now I know I cannot trust my imagination to see what is going on in the threading. I must write it down.

No, I did not rethread. This is only a sample. And seeing these two errors over and over again as I weave will reinforce what I need to do from now on. Hopefully................!

2 comments:

Dorothy said...

There is so much to know about weaving. Maybe this hadn't happened to you before just out of good luck, and because of an accident you've got a different understand of working with blocks.

An issue I see here is that weaving software is a fast way to get designs worked out, but in terms of thorough preparation I suspect there's no substitute for the step-by-step approach you have to take when drafting by hand. Using software, it's quite possible to overlook things like this.

I recently forgot to check float lengths in a pattern. Although the top surface in an advanced twill I'd designed was fine there were some ridiculously long floats on the back - and I didn't realise until it was off the loom. I need to organise a mirror for looking under the cloth on the loom, as I've seen you recommend!

Leigh said...

Yay for samples! We all knew there was a good reason for them, *lol*. Anyway, I never would have noticed that error from my galloping horse.