Simthread to Madeira color converter

Yes — that's the main thing it's for. Purchased embroidery designs usually list their colors in a commercial brand like Madeira, and the Simthread set from Amazon doesn't come with those numbers on the spools. Search the Madeira number from your design's thread list here and the chart gives you the Simthread spool that matches it, using Simthread's own published equivalences.

Treat them as close matches, not guarantees. This is Simthread's own published cross-reference — they're the ones saying which of their colors stands in for which Madeira color — but different manufacturers dye their own lines, and dye lots vary. For background colors in a design, take the chart's answer and stitch. For a color that carries the design, run a test stitch first.

Because Simthread hasn't published one. Their Madeira Rayon cross-reference covers S001 through S107, and this page won't invent matches they didn't publish. For a spool above S107, match by eye against a physical Madeira color card, or ask Simthread — their charts live on the downloads page of their site and get updated over time.

Not for the conversion, and rarely for the stitching. Both are 40-weight embroidery threads, so a design digitized for one runs with the other. The visible difference is sheen: rayon has a softer luster, polyester reads slightly brighter. The practical difference is durability: polyester holds color through hot washes and bleach better, which is why it dominates garments that get laundered hard.

Not directly — Simthread doesn't publish an Isacord cross-reference. What embroiderers do in practice is chain two charts: look up the Madeira equivalent here, then put that Madeira number into the Madeira-to-Isacord converter on this site. Chaining two nearest-matches can drift further than one, so give the result the test-stitch treatment before you trust it on visible work.

Because Simthread publishes their chart as a printed color card, not as screen color values, and a guessed swatch is worse than none. The names here are Simthread's own, which are descriptive enough to keep you oriented. When the color matters, the physical color card that ships with Simthread kits is the real reference.