Isacord is the workhorse of machine embroidery: a 40-weight trilobal polyester that runs at high speed without shredding, shrugs off bleach and repeated washing, and keeps its sheen for the life of the project. It's the thread commercial embroiderers standardize on, and Linda's now stocks the wall — 472 Isacord colorways, including solids on 1000m spools ($6.99) and 5000m cones, plus the variegated Multi line ($11.99).
Why Embroiderers Standardize on Isacord
Trilobal polyester has a triangular cross-section that reflects light like rayon but with far higher tensile strength. In practice that means fewer thread breaks at high stitch counts, no special handling on dense fill designs, and colorfastness that survives commercial laundering. If you're stitching gifts, garments or anything that gets washed, polyester beats rayon — and Isacord's 40wt is the standard weight nearly all embroidery designs are digitized for.
Navigating 472 Colors
Isacord's numbering groups colors by family: 0000s run white through grey and yellow-neutrals like 0861 Tantone, 1000s cover oranges and browns like 1351 Starfish, 2000s the reds and pinks like 2600 Dusty Grape and purples like 2905 Iris Blue, 3000s the blues from 3410 Rich Blue and 3510 Electric Blue to icy pastels like 3650 Ice Cap, 4000s teals and aquas, 5000s greens like 6043 Yellowgreen in the 6000 yellow-greens. The Multi 9000 series adds variegated show-offs like Multi 9924 Atomic Orange.
Machine Settings That Work
Run Isacord with a 75/11 embroidery needle for most fabrics (90/14 on denim or canvas), a lightweight 60wt bobbin thread, and standard embroidery tension. It also makes an excellent decorative quilting thread on longarms and domestic machines when you want shine that cotton can't give.
Frequently Asked Questions
Is Isacord polyester or rayon, and does it matter?
Isacord is trilobal polyester. It has rayon-like sheen with much higher strength and full colorfastness — it survives bleach and hot washing, which rayon doesn't. For anything that gets laundered, polyester is the safer choice.
What weight is Isacord and what needle should I use?
Isacord is 40wt, the standard weight embroidery designs are digitized for. Use a 75/11 embroidery needle on most fabrics and a 90/14 on heavy materials, with 60wt bobbin thread underneath.
Can I quilt with Isacord?
Yes. It runs beautifully on longarm and domestic machines as a decorative quilting thread, adding sheen and strength — just pair it with a matching or neutral bobbin thread and standard tension.
Related Guides
- Why Some Quilters Choose Aurifil Thread — the cotton counterpart to Isacord's polyester
- Riley Blake Machine Embroidery Design USBs
- Interfacing, Stabilizers and Fusibles at Linda's
