How to Sample Mixed-Yarn Overshot for Uneven Shrinkage Before Weaving the Full Piece

Overshot combines a plain-weave ground with a supplementary pattern weft. The tabby and pattern picks alternate, and the design includes pattern areas, tabby areas and halftones. Your test therefore needs to reproduce those different areas rather than show only a small patch of pattern floats. Vermont Weaving Supplies: Understanding Overshot

Differential shrinkage means that yarns contract by different amounts during wet finishing. Fiber names alone cannot predict the result: even different wool yarns do not necessarily shrink equally. Handwoven: Harness the Power of Differential Shrinkage

Dense overshot can restrict yarn movement, but density does not eliminate the possibility of uneven shrinkage. In her answer about a cotton-ground overshot coverlet, Madelyn van der Hoogt explains that merino pattern weft can still full and shrink within a dense structure. That makes the combination of yarn, structure and finishing method the relevant test. Handwoven: Ask Madelyn—Yarn Shrinkage in Overshot?

Before sampling, describe the surface you want in observable terms: a flat ground, clearly readable motifs, a softly raised pattern or deliberate puckering. Also decide whether straight edges and consistent repeat dimensions matter for your piece. These criteria will help you judge the finished cloth without relying on a single shrinkage percentage.

Ashford recommends a 6–8-inch square as a general starting point for weaving samples, followed by wet finishing and reassessment of sett. For overshot, treat that size as a starting point: enlarge it when necessary to include complete motifs, ground areas and the transitions between them. Ashford: Let’s talk about setts…

For this test, aim to include at least two complete repeats in the direction you want to compare. Repeated motifs let you see whether a change occurs consistently or only near an edge. Include the intended side border and a representative end border or hem section if those are part of the design.

A narrow sample is useful for screening yarn choices. For the final confirmation, sample at the intended weaving width when practical. The New York Guild of Handweavers’ sampling guidance identifies full-width sampling as the most accurate option for the particular loom, width, sett and beat. It also notes that moving between loom types can change the beat. Sally Orgren on Sampling

If you sample at the beginning of the project warp, reserve enough length to remove the sample, finish it and tie on again. Stop the project after sampling until you have assessed the dry cloth. If a narrow trial leaves the edge behavior uncertain, use a full-width confirmation before weaving the remaining length.

Start with the yarn combination you actually intend to use. Record the yarn name, fiber content, size, ply and any stated treatment for each role: warp, tabby and pattern weft. Keep the labels with the sample so that a later substitution does not accidentally become part of the comparison.

The following is a proposed comparison plan, not a standardized textile test. It isolates a practical question: does changing the pattern yarn improve the finished structure?

Sample	Construction	Purpose
A: intended combination	Planned warp, tabby and pattern weft; planned sett and beat	Establish what the proposed piece does
B: pattern-yarn comparison	Same warp, tabby, draft and sett; alternative pattern yarn	Compare finished motif shape and surface
C: confirmation	Selected combination at intended width, with borders	Check the arrangement you will use for the full piece

Choose a comparison pattern yarn of similar thickness and construction when possible. If the alternative is much thicker, firmer or more loosely spun, record that difference. The comparison can still help you choose a cloth, but it cannot isolate fiber shrinkage alone.

Keep warp tension, treadling and beat as consistent as you can. Record both pattern picks and tabby picks per measured distance, or state clearly that your picks-per-inch figure includes both. If you later test a different sett or beat, make that a separate comparison rather than changing several things together.

Weave the actual overshot sequence, including its tabby picks, complete repeats and planned borders. Follow the draft’s notation carefully; record any changes you make to the number of pattern picks within a block.

Use this marking sequence so that the same locations can be found after finishing:

1. Assign each sample a short identifier and mark the warp direction.
2. Secure the beginning and end before cutting, keeping the measurement area clear of the securing stitches.
3. Place loose, contrasting thread markers at four points around an interior rectangle. Do not pull the markers tight or connect them with a taut thread.
4. Identify one complete motif inside that rectangle for separate width and height measurements.
5. Photograph the sample beside a ruler, showing its identifier and orientation.

Choose marker positions that are easy to recognize in the structure, such as the same boundary in successive repeats. Measure between the marker points rather than including fringe or an irregular cut edge.

If you want an unfinished reference, weave an additional matching section. An intact reference is especially useful for comparing float definition and surface texture. Cutting a small motif in half may remove the very structure you wanted to assess.

Use three separate measurement stages: on the loom, relaxed off the loom and dry after finishing. This proposed record keeps release from loom tension separate from the dimensional change produced by the finishing process.

Measure the off-loom sample resting flat without pulling it square. Record the following at every stage where practical:

Measurement	Where to take it
Overall width	At three identified crosswise positions
Interior width and length	Between the same marker points
Motif width and height	Across the selected complete motif
Border behavior	Along each edge and where the border meets the pattern
Surface appearance	Ground flatness, float definition and visible puckering

Keep the three width readings rather than replacing them immediately with an average. A sample that narrows mainly through one patterned section needs a different decision from a sample that contracts evenly.

Also note anything already uneven before washing: a bowed border, inconsistent beat or a motif that is taller at one side. Pre-existing differences should remain visible in the record instead of being attributed automatically to wet finishing.

Use the finishing method you intend to apply to the full piece. A sample finished under different conditions answers a different question. For cotton-ground overshot with merino pattern weft, van der Hoogt specifically recommends careful cool-water soaking and rinsing without agitation as an alternative to dry cleaning. Her advice concerns that combination; it is not a universal recipe for every mixed-yarn cloth. Handwoven: Ask Madelyn—Yarn Shrinkage in Overshot?

Before starting, check the yarn makers’ care instructions and write down the proposed procedure. Include water temperature, washing product and amount, soak time, handling, rinsing and drying method. Finish A and B using matching conditions.

For the initial assessment, let the samples dry without stretching them into shape. Measure them dry before any pressing or blocking. If pressing is part of the intended final finish, apply it afterward and record a separate set of observations. This preserves the distinction between the cloth’s initial finished shape and the shape produced by that additional step.

If ordinary later washing matters to your project, put the chosen sample through that intended wash-and-dry routine again. Record the second result separately. Do not assume that the first finish represents every later treatment.

For each marked dimension, calculate wet-finishing shrinkage from its relaxed, dry, off-loom measurement:

Wet-finishing shrinkage (%) = (before finishing − after finishing) ÷ before finishing × 100

The following numbers are illustrative, not measured results:

Marked dimension	Before finishing	After finishing	Reduction
Interior width	20 cm	18 cm	10%
Interior length	25 cm	21 cm	16%
Selected motif width	5 cm	4.2 cm	16%
Selected motif height	5 cm	4 cm	20%

Here, the interior width contracts by 10%, while the motif width contracts by 16%. The six-percentage-point difference is a reason to inspect that area closely. It does not establish the isolated shrinkage rate of the pattern yarn, because these are measurements of interlaced cloth.

Measure the three overall widths again and compare their changes individually. Look for puckers beside patterned areas, narrowed bands, curved borders and differences between repeated motifs. There is no pass percentage proposed here: the decision depends on the surface you intended.

For planning a finished dimension, divide the target dimension by the retained fraction. With an illustrative 10% width reduction, a 30 cm finished width requires 30 ÷ 0.90, or about 33.3 cm, at the same pre-finish measurement stage. Simply adding 10% gives 33 cm. Keep this calculation separate from allowances for draw-in, loom waste and other stages of the weaving plan.

Assess the sample against your original criteria after it is fully dry. Use the following decisions to connect observations with the next useful test:

Observation	Next action
Repeats change consistently and the surface is as intended	Confirm the selected combination at project width if the trial was narrow
Puckering concentrates around pattern areas	Compare the alternative pattern yarn before changing the whole construction
Unevenness was present before finishing	Correct the recorded weaving inconsistency and repeat the test
Only borders distort	Sample the border-to-pattern transition again, changing one relevant feature
The intended finish produces an unwanted surface	Test another yarn combination or finishing procedure before continuing
The sample changes further in the second wash	Base the decision on that later result and record the additional change

If you change sett, sample again. Ashford’s examples show that sett affects the finished fabric’s feel and structure; it is not merely a dimensional adjustment. A closer sett should therefore be treated as a new construction to evaluate. Ashford: Let’s talk about setts…

Keep the chosen sample with its draft, yarn details, measurements and finishing record. Proceed when that specific combination gives the repeat shape, surface and edges you want. The useful result of sampling mixed-yarn overshot is a reproducible plan for the full piece, supported by both measurements and a piece of finished cloth you can examine.

• Understanding Overshot — Vermont Weaving Supplies
• Let’s talk about setts… — Ashford Wheels and Looms
• Ask Madelyn: Yarn Shrinkage in Overshot? — Handwoven
• Sally Orgren on Sampling — New York Guild of Handweavers
• Harness the Power of Differential Shrinkage — Handwoven