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.

Instructions for a simple 3/1 broken twill pattern without a graph

Diamond in 3/1 broken twill3/1 broken twill is a type of tablet weaving that produces a very pronounced diagonal structure in the weave.  This weave is particularly suitable for designs that are very diagonal, and in this case a friend requested a yellow belt with hollow green diamonds.  In this article I am going to write how I set up the cards and arranged the turning sequences so that the weaving speed was maximized.

To maximize weaving speed, you need to arrange the cards so that they can be turned as a group, and are manipulated as little as possible.  Here, the only manipulation of cards will occur when we flip a card around its vertical axis.

 

Basic Set up

The pattern area consists of 32 cards, each threaded with two dark (green), and  two (yellow) threads.  For the first 16 cards (counting from the left) we thread the cards as below, where the woven area extends to the left, and the warp to the right, and repeating the cycle of four cards four times (since 4×4=16).

Setting up the Cards

Note that cards 1 and 3 “mirror each other” in that they have the threads going through the same holes, and similarly cards 2 and 4 mirror one another.

For the second set of 16 cards we mirror the first 16 from the centre out, so that card 17 is threaded like 2, card 18 like 1, card 19 like 4 and card 20 like 3, and then keep repeating.

Lastly we divide the cards into two packs we call “Odd and “Even”.  The “Odd cards” include all the odd numbered cards from 1 – 15, and all the even numbered cards from 18 – 32.  The “Even cards” include all the even numbered cards from 2 – 16 and all the odd numbered cards from 17 – 31.  Note that all the “Odd” cards should have the light in the front two holes, and all the “Even” cards should have the light in the top two holes.

Basic Setup (short version):

The cards are all threaded 2 dark, 2 light.  Threading alternates in pairs (i.e. SSZZ).  Separate the cards out into two packs:

  • The Odds include the odd numbered cards between 1 and 16 and the even numbered cards between 17 and 32.
  • The Evens include the even numbered cards between 1 and 16 and the odd numbered cards between 17 and 32.

Checking the Setup

If the cards were threaded correctly, all the Odds should all have the light in the front two holes (Top and bottom), the Evens should have all the light threads in the top two holes, and in each of the two packs the threading should now alternate between S and Z.

This position is called the home position. The Odds are in Vertical Front and the Evens are in Horizontal position.

Turning directions

When you first start turning, you want to use the following turning directions.  This should produce a structural background consisting of diagonals meeting at a point in the center.

Pick Oddish Pack Even Pack
1 Forward Forward
2 Forward Back
3 Back Back
4 Back Forward

To reverse the direction of the chevrons, your options are to either flip all the cards in the Even pack when the cards are in the home position or to switch over to the alternate turning sequence, where the Oddish Pack still moves exactly as before, but the Even pack changes directions, resulting in:

Pick Oddish Pack Even Pack
1 Forward Back
2 Forward Forward
3 Back Forward
4 Back Back

It is important that you flip the cards, or change the turning direction, when the Even pack is in the Horizontal position.  Other wise, they all suddenly switch to the foreground colour, which is known as an oops.

Adding the Pattern

After weaving the background for a while, it’s time to start adding the pattern.  Colour changes happen by flipping a card on its vertical axis when it is in Vertical position.  Hence if the light (yellow) thread was in the two holes closest to you, they would now be in the two holes furthest away after the flip.  Also, the threading direction is reversed.

The diamond pattern is very basic.  The first change is made after pick 3: the two center cards – both in the Evenish decl – are flipped.  Then the next turn is made.  (If the points do not make a V, undo the turn, unflip the cards, and weave picks 4 and 1.)

On the next pick, the Oddish cards are in vertical position: flip the middle 2 cards.  They will be the cards just to the outside of the central cards in the Evenish deck.  Weave the next pick.

On the next pick the Evenish cards are in vertical position.  Flip the cards outside the 2 previously flipped cards, and unflip the previously flipped cards.  Weave the next pick.

Keep repeating the flipping of the next outwards cards (and unflipping the current cards) until you reach the width you want.  I’m going to assume that you kept expanding the diamond until the Evenish cards are in horizontal position and you are about to weave pick 1.  Instead of flipping cards, switch from one set of turning directions to the other.

After this first pick, again flip cards as you did before, but instead of flipping the next card to the outside, flip the next card to the inside.  (You’re walking the diamond back to a point.)  And keep going till all the cards are unflipped again.

If you decide not to unflip cards as you go along you will get a solid coloured diamond instead.

Danskbrogd – a Norwegian Textile technique

The Norwegian Textile Letter is a free online quarterly publication that covers – as the name suggests – a wide variety of Scandinavian textile arts.  Both the current issue and previous issues dating back to 1994 are available online as pdfs, and they make for fascinating reading.

The current issue is part one of a two-parter (part two publishes on Aug 22nd) that covers the Danskbrogd technique for weaving coverlets.  This technique is defined both by its originating location (Vest Agder, Norway) and by the geometric patterns that are woven in widthwise.  Danskbrogd, A Rich Heritage from a Small Area is the first article in part one, and includes a good overview including some lovely exemplars.  The last picture they include is of a modern design featuring honeycomb and bees.

I have some warp in a warp chain.  I need to get it on a loom and play with it.

 

Playing with Baltic Pickup style inkle weaving (Part 2)

Baltic Pickup GamesSo I spent some time this weekend playing with the Baltic inkle pickup warp.  The rules of the game were simple: two repeats of the simple diamond with the 4 interior diamonds, alternating with a diamond with some other free-styled pattern.

By keeping the edging pattern between the diamonds and the outer diamond’s dimensions consistent, the band feels cohesive, even though every third diamond is something else.  Below are 16 possible variations I came up with, while enjoying a Columbo marathon.

Variations on a ThemeOh, and just one more thing … there are 25 places where the warp thread can be pushed down, or not, inside the diamond.  That means that there are 2^25= 33554432 possible combinations, but I’m guessing that many of them lack pleasing symmetries.

 

Back of the envelop suggests that requiring symmetry along one diagonal reduces the possibilities to about 2^10+2^5=1024+32=1056 (the places below the diagonal line plus the diagonal line), but then the diagonal line can itself be flipped …  But the “S” figures are flipped around a vertical or horizontal line; so there are 4 possible axis of symmetry, so 4*1056= 4224 possible combinations that are symmetric.

In short, back of the envelop suggests that I’m going to run out of warp before I run out of possibilities.

Playing with Baltic Pickup style inkle weaving

Threading diagramBaltic pickup style inkle is woven using background threads and pickup threads; the pickup threads are usually either thicker, or doubled up.  In the threading diagram, you can see how each pickup thread is place between two threads in the opposite heddle; the white boxes representing the pickup threads.  In the diagram one row represents the heddled threads and the other the open threads, and the rows aren’t labeled since it actually doesn’t matter which is which in this case, so why complicate things?

 

The patterns here use 17 background threads; the 5 leftmost and rightmost threads are woven over a green background, while the middle 7 pick up threads lie nestled between dark blue background threads.  The plan is to eventually experiment with the Kostrup patterns, since those are 17 cards wide also, but I needed simple patterns to weave while out and about Monday.

The current patterns are simple diamonds, and by weaving them upside down I only ever have to drop threads from the current row, rather than having to pick up.  In the pattern (Baltic Diamonds) squares with circles in them are the pickup threads that are high in each row.  If a pickup thread is high but has a grey background, then it gets dropped, resulting in the front patterns we see on the left below.

Small Diamonds (back side)Small Diamonds (front side)This is what the pattern with the small diamonds looks like; the predominantly green/blue side is what you see while weaving, the white side is the underside which is much harder to photograph while on the loom.

 

 

 

 

 

 

Large Diamonds (back side)Large Diamonds (front side)Here I was working with larger diamonds, and experimenting a little with alternate patterns like the diamond in a diamond and the inner cross.  Making the outside diamond a little smaller results in a 2×2 grid of the smaller diamonds, or a 3×3 grid of the larger, and then it’s just a matter of dropping a few extra threads here and there.

 

 

 

 

 

 

 

Final update on the Kostrup weaving

Sunday was the moment the weaving came off the loom. Total woven length is 1.36m.  And the wool used in the brocading is the same weight as the wool used in the weaving, except that the brocade uses doubled threads.  For the weft I used 60/2 silk, and in a next product I might go thinner still.

Kostrup weaving fresh off the loom

As you can see from this first picture, I handled the colour changes by cutting the brocading thread at the end of each colour.  Each woolen brocade thread passed through one weft after it’s done brocading; given the stickiness of this wool, that should be more than enough to anchor it in place. In some cases, like the small triangles, you use two colours at the same time; even beating extra hard I struggled to get both brocading wefts to lie in the weft without a smidge of gappage.  In a next attempt, I think it might be better for those areas if the brocading weft does not go the width of the band, but instead goes only part way.

 

On the other hand, once the band relaxed off the loom, the occasional gaps between successive lines of brocading improved already.
Kostrup weaving with threads trimmedTrimming the ends of the brocading threads carefully,  you can see that the brocading threads are visible on the back only where it moves from pick to pick; I dropped the brocading threads two cards from the edge (or halfways through the 4 card selvage), so that there wouldn’t be any colourful bumps on the very end.

Next step is to take it to the post office tomorrow and mail it off, and then I want to experiment with some pattern variations.

Continuing the Kostrup weaving part 3

Progress on weavingProgress remains painfully slow, although the netting needles have helped tremendously in picking out the pattern, and I have finally developed a rhythm of sorts.

By evening last night I had finished the first 30 cm, which was one repeat of the patterns in the paper.  I’m going to weave about a 3cm break and then repeat the set of patterns.  Three repeats should get me pretty close to a meter.

The biggest problem so far is that the wool sticks to itself, and so I am having to reverse direction sooner than I am used to, just to keep the wool from felting.

Well, that and occasionally a card sneaks in a quarter turn, and it takes me a while to notice and fix it.

Losing track of time …

We’re heading to the middle of February, and time has been getting seriously away from me.  Gulfwars XXV is just over a month away, and there’s a lot I have to get done before then.

I’m teaching a week long series of tabletweaving classes; we start warping on Monday, and end on Friday with 3/1 broken twill, stopping to play with simple patterns, as well as Egyptian Diagonals and doubleface before we get there.

Which means I have been writing teaching handouts; it was time to take some of the old ones out and refurbish them.  And I’ve added a new one which introduces some very simple patterns on the same warp you can use for the fancier patterns: Tabletweaving Starter Class Handout.

 

And while working on that, I also found an old class handout from a few years ago, that explains how to play Rithmomachy (Rithmomachy Class Handout)- a game that was played from the 11th through the 17th century, primarily in monastery schools, where it served as an excellent way of reinforcing students’ abilities to add, subtract, and factor.  I keep wondering if we could reintroduce the game to modern students …

Using inkscape to draft tabletweaving patterns

I draft a lot of patterns for tabletweaving, and the way I like to display the pattern includes both the turning directions and a guideline as to what the pattern should look like.

When I first started drafting patterns, I would work in pencil on gridded paper where each square represented one card in one row; first I would outline the main shapes, and then use a highlighter to add the turning directions for each card — highlighted for backwards, not highlighted for forwards. The biggest downside was that even at 5 squares per inch, a sheet of standard letter paper didn’t really hold room for a lot of cards. And heck, the squares could be smaller in any case.

I use computers a great deal, so casting around for solutions I experimented (briefly) with spreadsheets and discovered that this was too fiddly for me. Then I discovered Adobe Illustrator, which is a vector based graphics editor that has all the bells and whistles one could desire. Sadly, it also had a price tag to match, and I was at the time a graduate student, and student discounts are nice, but not *that* nice.

Which brought me to inkscape which is free, opensource, and available for Windows, Mac OS, and most importantly linux, aka my operating system of choice.  Inkscape is a very powerful program, but I take advantage of a limited number of features.

blank_patternI use layers extensively, as each part of the pattern is in its own layer, including the grid. In fact, I usually use the following layers from top to bottom:

  • Grid lines – black grid lines 0.5 px wide
  • White grid lines – white grid lines 3.5 px thick
  • Pattern – one layer per colour to make colours easy to manipulate
    • Colour 1 – line 3 px wide
    • Colour 2 – line 3 px wide
    • Rough Pattern
  • Threading – the colour in the dots indicates the colour of thread in the two top holes.
  • Greyscale – used to indicate the turning directions forward and back.  Grey squares are turned towards the weaver, and white squares means the cards are turned away from the weaver.

Setting the layers up in this way allows me to take advantage of the order in which they’re drawn (bottom up) so that the diagonal lines I draw in the pattern colours become small individual diagonals.

rough_patternOnce I have the layers set up and the grid built I usually save the file as a blank.svg file, so that I don’t have to keep rebuilding the grid.

In this case, I’m planning a very simple pattern where the cards turn continuously in one direction until twist builds up, and then they reverse direction. I’ve roughed it in and now it’s just a matter of adding the colours.

finished_patternThe basic design has all cards threaded the same way with two dark and two light colours, and we will be turning the cards forwards 12 times, and then backwards 12 times.

pattern_2In this simple variation, we have turned every second card around its vertical axis, so that half the cards are threaded from left to right, and the other half are threaded from right to left.

Weaving Class 19 Dec, 2015

Today I am teaching two classes on tabletweaving covering the methods of doubleface and brocading.  This post is primarily intended as a resource for that class, and includes links: