Before You Start Tablet Weaving — a Checklist

Tablet weaving is fraught with trapdoors, little mistakes that are easy to make. This pre-weaving checklist may keep you from falling into one.

First, some background. The weaving competition at the Minnesota State Fair is a big deal. Every year more than a hundred Minnesotans compete for ribbons and cash prizes in about two dozen weaving and spinning categories. In addition, the Weavers Guild of Minnesota awards a dozen special prizes based on quality criteria such as “best use of color in a woven wearable item”.

The Guild’s band-weaving study group, waggishly named Banditos, weaves and assembles ribbons that the Guild awards. Volunteers weave streamers, pleat rosettes, print medallions, and gather in late July to glue them together.

LJ, a good friend and member of Banditos, was having trouble weaving streamers from a pattern found on Pinterest. The pattern was threaded-in (turn four forward, four backward, and repeat), so weaving should have been straightforward.

The Pinterest post is a screen-shot from the Windows-based tablet-weaving app Guntram’s Tablet-Weaving Thingy (GTT). The screen-shot shows a threading diagram and the turning sequence that will result in a band looking like the graphic on the left. The post includes a photo of a band woven from the pattern:

LJ threaded her cards with colors chosen for this year’s ribbons using UKI perle cotton, substituting colors Melon for black, Stone for both shades of gray, and Quarry (a slightly greenish shade of blue) for light white. Here’s the GTT-generated pattern with LJ’s choice of colors:

LJ’s woven result shows that something is clearly amiss.

The center stars are unrecognizable, and the diamonds framing them have jagged edges. This is a sign that twining is backwards, an effect caused when the weaver either turns tablets the wrong way or threads them the wrong direction.

LJ has some experience tablet-weaving, so I was sure that she knew the difference between turning forward and backward. And she knows the difference between S- and Z-threading

I was stumped. I suggested that she rip out her weaving and then, before starting again, ask herself these questions. (All should be answered affirmatively when following a pattern taken from GTT.)

• Are your tablets ordered left to right, as you view them from the front of your loom?
• Are the tablets’ front sides facing to your right?
• Are your tablets’ holes labeled A-D clockwise on their front faces?
• Are your tablets in correct starting position for a threaded-in pattern: hole A in the far-top position, and hole D near-top?
• Are the cards threaded correctly? GTT uses S and Z to indicate thread slant: A tablet is S-threaded if warp threads pass through its holes at an angle parallel to the main diagonal of the letter S; or equivalently, if the tablet leans to the right when the warp is under tension.
• When you start weaving, are you turning tablets forward or backward using the “bicycle wheel” analogy? That is, turning a tablet forward makes the top of the tablet turn  away from you.

LJ went through the list twice; the second time she realized that her tablets were ordered from right to left. After re-arranging the tablets (leaving threading unchanged), her weaving was fixed!

LJ’s experience led me to wonder where the process might have gone astray. I know she has woven from other tablet-weaving patterns, but this may have been her first experience weaving from an online image of a GTT-generated pattern. Could GTT have somehow been the culprit?

I’ve been using GTT since 2012 to design virtually all of my patterns. This Windows app has been around since the very early 2000s. At the time of GTT’s inception it was the most sophisticated tablet-weaving design application around, supporting the design of threaded-in, double-faced, 3/1 broken twill patterns, and even fonts for double-faced lettered bands.

It is still popular today with tablet weavers. For example, when searching Pinterest.com for “tablet weaving patterns”, 30 of the first 59 results showed GTT-generated patterns.

The application, unfortunately, shows its age. Its user interface is 1990s vintage. And it is missing some basic CRUD (developer speak: Create-Read-Update-Delete) operations, such as the ability to insert rows in a weaving diagram, or change the turning direction of a tablet in a pattern without erasing all subsequent rows and starting over. Over the years I’ve developed hacks to work around its weaknesses, for example, to create patterns that I can print and weave from.

I believe that this post illustrates how LJ may have been led astray by the somewhat idiosyncratic way that GTT displays threading diagrams. GTT can display three versions of threading diagrams, two for display and one for editing. To create a new threading diagram or edit an existing diagram, either press the tablet icon in the menu bar or click on Edit > Card List.

Clicking on View > Display > Show Card Threading displays a non-editable threading diagram directly below the weaving illustration.

Finally, a printable version of the diagram appears in a pop-up window when pressing View > Threading Diagram or pressing the “Threading Diagram” icon in the menu bar.

This diagram is displayed with tablets listed vertically and holes horizontally, running counter to the common convention of displaying one tablet per column and one hole per row, with tablets numbered left to right, and even counter to the way GTT displays the other two threading diagrams.

The viewer of that Pinterest post, attempting to transform this threading diagram to a familiar form, might try to view it sideways …

… which, unfortunately, shows tablets ordered right to left. Even worse, tablet threadings are backwards: weaving from this diagram, when tablets are ordered right to left, will produce the errors that LJ experienced.

To correct the tablet order and threading, the sideways diagram must be flipped horizontally:

This diagram now displays the pattern correctly in a format generally accepted as standard in the tablet-weaving community — if one ignores text being sideways and backwards.

So, to correctly interpret and weave from this diagram requires not inconsiderable mental gymnastics — or the computational gymnastics, as I have done here to use image-processing software — to do the translation and flipping of GTT’s diagram.

Tablet-weaving is inherently complex, presenting the weaver with many opportunities for making errors. It is unfortunate when the software actually increases the chance of introducing errors. You can eliminate many of those errors before starting to weave by taking a 5-minute time-out and answering these these questions (duplicated from earlier in this post).

• Are your tablets ordered left to right, as you view them from the front of your loom?
• Are the tablets’ front sides facing to your right?
• Are your tablets’ holes labeled A-D clockwise on their front faces?
• Are your tablets in correct starting position for a threaded-in pattern: hole A in the far-top position, and hole D near-top?
• Are the cards threaded correctly? GTT uses S and Z to indicate thread slant: A tablet is S-threaded if warp threads pass through its holes at an angle parallel to the main diagonal of the letter S; or equivalently, if the tablet leans to the right when the warp is under tension.
• When you start weaving, are you turning tablets forward or backward using the “bicycle wheel” analogy? That is, turning a tablet forward makes the top of the tablet turn  away from you.

Happy tablet-weaving!