Polyester Tartan Ribbon: The Sett Has to Fit the Width

Polyester tartan ribbon is a plaid reduced to a width, and the reduction is where the problems live. A tartan is defined by its sett: a fixed sequence of colour bands, repeated in the warp and again in the weft. A full sett is measured in centimetres, and a ribbon is measured in millimetres, so the pattern has to be scaled down before it can be woven — and scaling a tartan is not a neutral operation. The proportions survive, the character sometimes does not.

This guide covers what a sett is and why it must be scaled, how registration between warp and weft makes a plaid rather than a stripe, which measurements show whether a tartan is square, six lines a tartan brief should carry, and the two defects that appear only on a multi-colour narrow weave.

Polyester Tartan Ribbon: Sett, Width and Scale

The relationship between the sett and the finished width decides what the ribbon can look like. There are only three practical outcomes, and a buyer who has not chosen one of them has left the appearance to whoever sets the loom.

The second option is the one that produces the most consistent product, because a single complete sett across the width means the pattern cannot fall differently from one cut to the next. A fraction of a sett produces a ribbon that is beautiful on the roll and inconsistent in a bow, since a length cut at a different point shows a different arrangement of bands. For a product sold in pre-cut lengths, that difference is visible on a shelf.

Three Measurements That Show Quality

Squareness, measured on the diagonal

A tartan is a grid, and a grid can be checked without any instrument beyond a rule. Measure the two diagonals of a single square formed by the crossing bands. Equal diagonals mean the square is square; unequal ones mean the cloth has been stretched along one axis, usually in the warp during finishing. The measurement takes seconds and it detects a fault that is otherwise described as the tartan looking slightly off.

The sett length, in millimetres

The sett has a length, and that length multiplied by the number of setts across the width should equal the finished width within a tolerance. If it does not, either the sett was scaled without adjusting the width or the width was adjusted without rescaling the sett. Both produce a tartan that looks approximately right and is not the pattern that was approved, and the discrepancy is measurable on any sample.

The colour count, and the weakest of them

A tartan uses several colours, and each is a separate dye with its own behaviour. Fastness is therefore not a single figure but the worst of the set, and the worst is usually the darkest or the brightest. A report that gives one number for a four-colour tartan is describing the best of them or an average, and neither is what a customer will see when one band fades faster than its neighbours.

Six Lines for a Tartan Brief

1. The sett, by name and by size — a named tartan plus the sett length in millimetres, since the same name is sold at several scales.
2. How many setts across the width — a fraction, one, or several; the choice decides whether every cut matches.
3. The colours, with a reference each — four bands means four dye decisions and four chances to drift.
4. The fastness per colour — asked for as a set of figures, because the weakest band sets the performance of the ribbon.
5. The cut length — which decides whether a full sett or a fraction is the right answer for the product.
6. Whether the reverse will be seen — the back of a tartan is a lighter version of the face, which is fine on a bow and wrong on a sash.

The sixth line surprises buyers who have only seen a tartan face-up. The reverse of a woven tartan is not a dull blank; it is the same sett in muted tones, because the floats that form the face are the binding points on the back. On a bow that reverse appears at every twist and reads as a lighter patch, and on a sash worn across a shoulder it is on display for the whole evening.

• Measure a square's diagonals — the simplest test in this guide and the one that finds a stretched tartan.
• Count the setts across — and check the arithmetic against the stated width.
• Look at the crossing, not the band — a shift of one pick shows at the intersections first.
• Keep a metre from the approved lot — a fourth colour is a fourth thing to drift.

A tartan is one of the few patterns that can only be woven, and the polyester ribbon range is woven on the same looms here in an 8,000+ m² plant in Dongguan as the polyester webbing that trims custom spec bags, so a sett can be trialled against the width it will actually be made in. A 25 mm webbing base clears 2000N; a tartan is measured in squares.

Two Defects Only a Multi-Colour Weave Has

A band that is one pick out

In a single-colour weave a misplaced pick is invisible. In a tartan it is a visible step: the horizontal band sits a pick above or below where the warp crossing expects it, and the grid acquires a row of rectangles instead of squares. The fault runs across the full width, so it cannot be trimmed out, and it is the reason a tartan needs its weft sequence checked at the start of a run rather than at the end.

One band that takes the dye differently

Four colours means four dyestuffs and, in a yarn-dyed tartan, four sets of yarn that must be dyed to their targets before weaving. A single band slightly off shifts the whole balance of the check: the eye reads the pattern as heavier or lighter overall even though three of the four bands are correct. This is why an approved standard for a tartan should be a woven piece and not a colour card, since the interaction between the bands is the product.

FAQ: Polyester Tartan Ribbon

Polyester tartan ribbon is a sett scaled to a width. Fix the sett length and the number of setts across, measure the squares, and ask for fastness per colour rather than for one figure.