Carbon Twill refers to cases built from carbon filaments woven into a fabric first, then bonded with resin. The name comes from the diagonal twill pattern the weave produces: a plain weave reads like a checkerboard, while twill shows a slanted, directional grain. That ordered, repeating texture is the key difference from forged carbon, which presses chopped fibres into a mould and yields a random, marbled look. Twill is the more decorative of the two, though a poorly finished case can fray at the edges, and it tends to absorb impact slightly less well than forged.
The most refined example is Richard Mille's Carbon TPT. Using North Thin Ply Technology, layers roughly 30 microns thick are impregnated with resin and rotated 45 degrees between plies, then cured at 120C under 6 bar, leaving a striated, almost wood-grain surface machined at the brand's ProArt factory. The RM 11 series (the RM 11-03 succeeded the discontinued RM 011) trades well above £240,000 on the secondary market. Ulysse Nardin's Carbonium, an aerospace composite of roughly two-thirds intermediate-modulus carbon fibre and one-third high-temperature epoxy, debuted in 2019; the Diver Net OPS (2024) is around £10,600 and the Diver X Skeleton OPS about £22,000. Further down, Bell & Ross BR 03 Carbon, Luminox Carbonox and Casio G-Shock's carbon-fibre resin bezels bring the look within reach.
When buying, scrutinise finishing: clean edges, even resin, and a pattern that stays consistent around the case. The appeal of twill is low mass and a crisp, legible texture; a good twill case feels markedly lighter than steel and catches light with real depth. The trade-off is that it does not soak up knocks like forged carbon, and the fine surface shows careless scratches more readily. It suits the collector who wants lightness, technical aesthetics and woven character, and who is willing to treat the watch with a little more care.
There are sub-types within the niche too: classic woven twill sheets (Carbonium, much of Carbotech) and the rotated thin-ply variant, Carbon TPT, which can take coloured quartz layers for striped effects. To tell true twill from forged, look for that regular directional grain across the surface; the repeating rhythm is the signature.