An Introduction to Weaving Gamps

A weaving gamp is a two-dimensional array of woven patterns. It is used as a tool to examine the interactions that occur at the intersections of each warp and weft variable—color, sett, structure, etc. In the most basic gamps, the variable is the same in both warp and weft. For example, in a classic color gamp, each warp-wise section is a different color. The weft-wise sections follow the identical color order.

An Introduction to Weaving Gamps

This color gamp uses all 9 colors of Gist Yarn’s Ode Alpaca. It’s a 2/2 twill sett at 12 epi on an asymmetrical extended point draw to add a little visual interest. The ends are finished with a hemstitch.

The Difference Between a Gamp and a Sampler

sampler compares a series of changes in the weft of a fabric, either the colors, the beat, the treadling, or some other element. 

An Introduction to Weaving Gamps

This small sampler uses Mallo sett at 15 epi on a small Structo loom. It explored various treadlings including plain weave and twills with different beats (picks per inch). The big lesson learned from this sampler is that because of Mallo’s texture, structure patterns are not easily discernible.

A gamp compares a series of changes made in both the warp and the weft. The diagonal will show the matched pairs—AA, BB and CC. The other squares will combine the variables—AB, BC, CA, etc.

Gamp Example

An Introduction to Weaving Gamps

This Duet plain weave sett gamp explores how the hand of the cloth changes at various setts and pick densities. It is sett at 12, 14, 16 and 18 epi and is meticulously beat at 12, 14, 16 and 18 ppi. At 12 epi and 12 ppi (bottom left corner), the cloth is flimsy and translucent, appropriate for a summer shawl or light curtains. At 18 epi and 18 ppi (top right corner), the cloth is dense and stiffer, appropriate perhaps for a tablecloth.

Different Kinds of Gamps

An Introduction to Weaving Gamps

This color gamp explores a 6-color palette of Duet yarns. It is sett at 16 epi for a 2/2 twill.

Some reasons for making a gamp

  • To see how colors in a palette interact, mix and blend, make a color gamp.
  • To explore the possibilities of color variation within a structure, make a color-and-weave gamp.
  • To test various setts (epi) and beat densities (ppi), make a sett gamp.
  • To experiment with how mixed fibers will change with wet finishing, make a gamp with mix & match fibers.
  • To appreciate how different threading and treadling patterns will interact with each other, make a structure gamp, like this strikingly complex twill gamp.

Determining the sett for a gamp

An Introduction to Weaving Gamps

This gamp combines all five of Gist’s in-house yarns. The yarns from left to right and top to bottom are Mallo, Array, Ode, Duet and Beam. Each square was 3” in the reed. To determine the sett for each section, I made a chart of all the yarns and chose an appropriate twill sett for each section based on the wraps per inch. Various shades and tints of gray show contrast without the distraction of color. Note the differential shrinkage in the rows and columns, which results from wet finishing. The Array shrunk significantly more than the others, while the Ode shrunk very little, creating a bump in the center of the gamp.

Gamp Chart

* WPI is measured twice—once with the threads just touching, and once with the threads tightly packed together.

** Plain weave setts and twill setts are based on my own WPI measurements.

How to Use Gamps

The most basic use of a gamp is as a study piece, just to explore. But what if you are one of those people who likes to do more with your handwovens than hang them in a closet to look at sometime later? 

  • Finish the ends with a fringe and use it as a wall hanging
  • Make a nice hem and use it as a hand towel in your guest bath
  • Sew it into a small bag to carry a knitting project

Whatever you do with it, once you’ve gotten the information you need from your gamp, record it and then get creative!

And what about the thrums? One of the arguments against gamps is that they can have as much (or more) loom waste as they do actual weaving length. One of my favorite uses of gamp thrums is planning the next project I’m going to make with that yarn.

An Introduction to Weaving Gamps

After making the Duet color gamp using a range of neutrals and seeing how the colors play with each other, I used the thrums to make color wraps to plan the stripes for a future project. The stripes here are based on the Fibonacci series.

Pitfalls

Trying to Include Too Many Variables

Too many variables muddy the waters and make it hard to discern what the effect of any single change might be. Keep your gamp simple. The goal is to generate a useful tool. If I think I want to examine more than one variable, I might warp enough yarn for 2 gamp lengths. For example, I might sley at several different setts, weave a plain weave gamp, re-sley the warp to better accommodate twills, and then weave a twill gamp. 

Making the Squares too Small

If the squares are too small, you may not be able to really distinguish the changes. In a sett gamp, for example, one goal is to get a sense of the hand of the fabric at each density. A tiny 1” square won’t be big enough to feel each section.

Poor Definition in Section Breaks

Subtle changes in a pattern or sett might be hard to see if the sections are not delineated. Using a different color yarn to frame each square can often make the difference between being able to measure a result and just getting an impression.

Beating Inconsistently

It’s easy to beat at whatever happens naturally on your loom - with your beater, your tension, and your arm muscle. It’s more challenging to beat a piece exactly square to your epi. However, usually you’ll want to take extra care to make your gamp blocks square both in epi/ppi and in its dimensions. I frequently have to unweave and reweave in order to get the correct beat on a gamp. Remember also, to get the most accurate numbers, let the tension off your warp before you measure and count.

Not Wet Finishing

To truly see how yarns in a piece of cloth will interact, they should be wet finished. Record the shrinkage, noting how the fabric fulls, the opacity, and the texture after finishing.

Steps for Designing Your Own Gamp

  1. Decide on the primary variable of your gamp—color, sett, structure, etc. 
  2. Graph your gamp. Draw a grid and label each of the squares with your variables. It may be useful to attach samples of the yarns.
  3. Determine how big your gamp will be. This will be based on the size of your loom, how many columns and rows you want, the yarn (thicker yarn will necessitate bigger sections), and other relevant factors. 
  4. Calculate your warp length, including loom waste. Here it is useful to know your minimum loom waste, front and back, for each of your looms. A smaller loom will generally have less loom waste.
  5. Add borders or grids if it will help with your analysis. Remember that there will be more draw-in at the selvedges of the gamp, so you may want to add some extra border ends there.
  6. Make it pretty (if you want to)! Plan from the beginning whether you will fringe or hem the gamp and adjust accordingly. Or just plan for it to live quietly in the closet, which is also OK!
  7. Remember to record dimensions before and after wet finishing so you have all the shrinkage information you need for future projects.

About Penny Lacroix

Penny Lacroix is a weaver, spinner, learner, teacher, historian and lover of all things fiber. When she’s not actively learning something, she’s sharing with others in one way or another—making something by hand, demonstrating at historic events, or teaching a class. With past careers as an engineer, a mom, a museum educator and a museum director, combined with her hobby as a historical reenactor, her worlds interweave in the creation of textiles and the study of historic textile tools. She is active in several guilds and fiber groups near her home base in Massachusetts. Photos by Dan Lacroix.

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