echo weave vs shadow weave

In a comment on my last post, Meg wonders whether I know the difference between echo weave and shadow weave.  Hmmm, I know that they are different, but I needed to go away and look at drafts before making this post.  Having done that I feel a little better informed, but the following observations are homemade and by no means expert.  Please do correct me if you are wiser than I am.

It strikes me that there are a number of design differences between the two, but one key structural difference.  The structural difference is in the way the weaves are treadled.  I have heard that shadow weave is close to a plain weave structure in its interlacements, while it is clear from my scarf that what I am getting with echo weave is pretty much a twill (in her recent Journal article, Bonnie Inouye says that “in its simplest form, echo weave is the same as a double-faced twill woven as a turned draft”), even though both are threaded in parallel in very much the same way.

Here is a small example of what is happening in echo weave:

The warp threads are alternately dark blue and light blue: each dark blue thread is offset from its light “echo” by 4 shafts. I have used a 4/4 tie-up here, although for my scarf I have been using a 3/1/1/3, but this makes it easy to see what is happening and gives a direct point of comparison with the shadow weave below.  The main thing is that with my weft (here plain white) I am treadling straight through from 1 to 8.  I might vary this – of course I will vary this! – with advancing patterns, point patterns and so on, but this is the basic principle.

If I take exactly the same warp and weft, however, and treadle on opposites, then I get this,

which is shadow weave.  Of course, it doesn’t look like shadow weave, and that is what I meant when I said that there are design differences as well as this structural difference.  For an echo weave I use a single colour of weft which can be completely different from the warp colours, while to make a shadow weave I use the same alternating colours in the weft as I used in the warp to get the distinctive colour-and-weave effect, thus:

Another design difference is in the sett.  Because of all those interlacements, shadow weave needs a plain weave sett.  Echo weave on the other hand is warp-faced.  The dense sett of the warp means that a lot of the weft disappears between the warp layers, giving that double-faced twill effect which Bonnie described.

I had a look at the chapter on shadow weave in A Weaver’s Book of 8-Shaft Patterns (Carol Strickler) to see the 4/4 tie-up was a rule or a choice, and it seems to be more or less a rule.  On page 67 it says “If the threading is Atwater method [which is what I have used], the tie-up is half-and-half”, and there is nothing about tie-ups in the section on variations.  I guess if you want all those interlacements then you don’t have much room for manoeuvre.  Echo weave is much more of a free-for-all, so lots of scope for experimentation, i.e. playing.

“echo weave vs shadow weave” was posted by Cally on 13 Aug 2009 at http://callybooker.wordpress.com