Musings about Pickup in the large …

The inkle pickup band I completed a while back and described in the two entries part 1 and part 2 (now with more patterns!) got me thinking about weave structures.  In inkle pickup, the warp threads are manipulated so that some warp threads (the pattern threads) either float above or below the band to create the patterns.  On an inkle band this can be done by hand; you’re usually working with less than a dozen pattern threads so while the picking of individual threads is tedious, it’s not insurmountable.

But that got me wondering how similar manipulations would work on wider fabrics.  After all, making clothes (or even pillows and bags) out of bands that are usually an inch or two wide is tedious.   And then I ran into a fascinating book A Practical Study of the Development of Weaving Techniques in China, Western Asia and Europe by John Becker, published posthumously after his collaborator Don Wagner tidied and reset it a little.  The book starts in China with essentially the same kinds of pickup patterns I had been doing, with monochrome silk weaving that had patterns based on the way the warp was manipulated.  I’ve been fascinated with the opportunities ever since.

That, in turn, led to reading the later chapters that discuss the drawloom.  In the drawloom, each pattern warp thread is threaded through it’s own separate “heald” which can be used to pull the thread up and down.  Usually the pattern would repeat across the width of the fabric, and each repeat would be called a “comber”.  Each heald is goes through the comber board (which has one hole per heald) but then the healds will be joined to pulley threads.  There are as many pulley threads as there are pattern threads in a singe width repeat of the pattern, and the relative heald in each comber (or repeat) is hooked on to the corresponding pulley thread, so that as the pulley thread is pulled up, the corresponding thread in each repeat is raised.

So let’s look at the implications of that.  Let’s say that we wanted to weave a fabric 21 inches wide, using a set of 20 epi (ends to the inch).  That’s 21×20 = 420 warp threads, ignoring for the moment selvage threads etc.  Now let’s say that our pattern was 28 ends wide per repeat.  The on the one hand, each pulley thread is attached to 15 healds (since 420/28 = 15) but on the other hand for every row I only have to manipulate 28 pulley threads.  In comparison for the baltic inkle pickup, I was manipulating 8 or 9 threads per row, so this is a three fold increase in numbers of cords to manipulate, for a 21 fold increase in width.  Sounds like an excellent improvement in efficiency.

Of course there are trade-offs; the warping will be a lot slower, as the set up for the pulleys will be a lot more complicated.  But the pulleys can be set up once, for that pattern width, and then reused.  The warp does need to be threaded through each heald individually but weaving on a 4 harness loom we’re threading the warp strings through heddles, so the time increase is not insurmountable there, either.  And if we warp long lengths at a time, we can improve efficiency.  After all, with the drawloom we can create any 28 thread pattern we like.

And the biggest tradeoff; finding a drawloom.  Inkle looms are easy to find or build, and inkle heddles can be knotted up while watching telly.  A drawloom gets more complicated.  Although I did find a book with drawloom plans, available online at The New Drawloom, (part 2) hosted by the University of Arizona ((Front Page).

So now my options are to find a drawloom for sale, or convince my long-suffering hubby to build me one.  Or possibly to frankenstein it on top of one of the looms I already own.

Leave a Reply