Why does the chart give a different Madeira number than the one on the design's colour sheet?

Designers' sheets are usually made by eye from a thread card, and charts are made by measuring colour values. Both are matches to the same Isacord cone; a ΔE under 2 between the two Madeira candidates means they are near-identical.

Under 1 is indistinguishable, under 2.3 very close, under 5 close enough for most work. Over 5 the two threads read as different colours side by side, and the chart should be treated as a starting point.

Can I convert a whole file at once?

Yes. Drop the file on the thread converter and every block is matched to the brand you pick, with ΔE per block. Files that store thread names (VP3, PES 5+) match by name and number; the rest match by colour.

Are the chart colours accurate?

They are manufacturers' RGB approximations, the same data Ink/Stitch ships. They are good enough to rank candidates, not good enough to replace a physical thread card for a customer's brand colour.

Embroidery thread conversion: matching Isacord, Madeira, Sulky, Robison-Anton and Brother colours

Every design comes with a thread list in somebody else's brand. The shop stocks Madeira, the design says Isacord, the machine screen speaks Brother numbers, and the customer wants their logo blue. Conversion charts bridge those, and understanding how they are made tells you how far to trust them.

How a conversion chart is made

Each thread brand publishes a colour card: a catalogue number, a name and a colour for every thread they sell, 300 to 400 of them for polyester embroidery thread. Digitising software carries these cards as lists of RGB values, and a conversion is a search: for a thread in brand A, find the thread in brand B whose colour is closest.

"Closest" is the whole question. RGB distance is a poor measure of how different two colours look; a difference that is invisible in a dark blue is glaring in a pale yellow. The converter and the conversion tables use CIEDE2000, the standard the textile and print industries use: colours are converted to the CIELAB space, which is designed so that equal distances look equally different, and the difference is expressed as ΔE.

| ΔE | What it looks like | |---|---| | < 1 | No visible difference | | 1–2.3 | Visible side by side to a trained eye | | 2.3–5 | Visible side by side; not noticeable on its own | | 5–10 | Clearly a different shade | | > 10 | A different colour |

A chart that gives numbers without ΔE is hiding how good each match is. Ours shows it for every row, and the summary line on each table says how many of a brand's colours have a match under 5.

Why charts disagree

Take Isacord 3620 Marine Blue. One chart says Madeira 1842, another says 1843. Both are right: they are two Madeira blues about ΔE 2 apart, and the Isacord sits between them. A designer's colour sheet made by holding cones together will pick whichever looked closer under that day's light.

Three other reasons: the RGB values behind charts are approximations from the manufacturers' own swatches, not measurements of the thread; brands discontinue and add colours, so an older chart matches to threads that no longer exist; and rayon and polyester versions of the same brand have different colour cards (Madeira Rayon and Polyneon are two lists here, as are Sulky Rayon and Polyester).

Converting a single thread

Pick the source brand, type the number, pick the target. You get the three closest threads with ΔE for each. If the best is under 2.3, use it. If it is between 2.3 and 5, look at the swatches: the second candidate may be closer in the direction that matters (a little warmer, a little darker). Over 5, the target brand does not make that colour; choose by eye from the two nearest, or use a different brand for that thread.

Converting a whole design

Drop the file on the converter. Every colour block is matched to the brand you select:

Files that store thread names and numbers (VP3, TBF, PES version 5 and later with named threads) are matched from the named thread's colour.
Files that store palette indices (PES with palette colours, JEF, HUS) are matched from the palette colour, which is Brother's or Janome's own approximation.
Files with no colours (DST, EXP, U01) cannot be converted, because there is nothing to convert; use the colour sheet that came with the design.

The result is a list you can print with the colour sheet: block, original thread, nearest match, ΔE.

Machine palettes are their own brands

Brother machines show colours from a 64-entry palette; Janome from 79. When a design was digitised in Isacord and saved as PES, the software mapped each Isacord to the nearest palette entry, and that is what the machine shows. Converting "Brother Embroidery" to Isacord is therefore a conversion of a conversion, and the ΔE values are larger. The Brother to Isacord table exists because people need it; read its ΔE column with that in mind.

When to stop trusting the chart

Brand colours. A customer's Pantone blue is a colour, not a thread. Convert the Pantone to a thread with the hex-colour matcher, then confirm the cone against the artwork under daylight. The chart gets you to two candidates; the cone decides.
Skin tones, pale pastels, greys. ΔE hides small hue shifts here that are visible in a stitch-out. Compare cones.
Metallics and variegated. Not in the charts. Match by eye.
Old designs. A 2010 colour sheet names threads that have been renumbered or dropped. Match the colour, not the number.

Keeping your own chart

Shops that stock one brand end up with a house conversion: the Madeira cone they use for every common Isacord number, chosen once by eye and written down. The converter's tables are a starting list for that; your own decisions, made with cones in hand, are the final one. Thread brands compared covers the differences between the brands themselves.