Forged Carbon vs Twill Weave: Which Should You Choose?
This is probably the question I get asked most. Someone sends a photo of their car, points at a part they want, and asks whether they should go forged or twill. The answer is not a cop out, it really does depend on the car, the rest of the look, and the vibe you are chasing. Both are real carbon fibre, both are prepreg, and both perform the job. The difference is character, not quality.
I run RB Innovations and I make parts in both finishes, so I have no horse in this race. Here is the straight version.
What is twill weave carbon fibre?
Twill weave is the classic look you picture when someone says "carbon fibre". Long carbon fibre tows are woven together in a diagonal over under pattern, usually 2x2, so you get that repeating chequerboard effect that catches the light and shifts as you move past it. The fabric we use is prepreg, which means it comes pre-impregnated with the exact amount of resin needed before it ever touches a mould. It gets laid up, vacuum bagged, and cured under heat and pressure.
Twill reads as traditional motorsport carbon. Think factory M Performance parts, factory CSL parts, the carbon you see on every supercar from the last twenty years. It is ordered, geometric, and feels engineered.
What is forged carbon fibre?
Forged carbon is a different animal. A lot of people online still repeat the idea that it is "chopped offcuts" or shop scraps pressed into shape. That is wrong, and it has put plenty of buyers off a finish that deserves a fair look.
The forged carbon I use is a purpose-built prepreg fabric. Short irregular tiles of carbon fibre are pre-impregnated with resin and set in a random orientation inside the fabric sheet. That sheet is then laid into a mould and cured under heat and pressure, same as twill. Because the tiles sit at random angles, the finish ends up with a marbled, cloud-like look that no two parts share. Each piece is unique.
Both fabrics are proper prepreg carbon. Both get cured under controlled temperature and pressure. The structural difference is the fibre orientation, which I will get to below.
Looks: the real reason most people choose
Be honest with yourself here, because this is the bit that actually matters to 90% of buyers.
Twill is timeless. If your car is a clean factory build, if you are going for OEM plus, or if the rest of the car already has twill (most interior trim, most factory carbon options), twill is the move. It fits in, it reads as correct, and it does not fight anything else on the car.
Forged carbon is louder in a subtle way. From three metres out it almost looks like stone or marble. Up close you notice the pattern keeps moving. It suits aggressive bumpers, wider arches, and cars that are already doing something different. On a CSL style grille or a big front lip, forged reads as a statement piece. On a small mirror cap next to factory twill interior trim, it can look a bit mismatched if the rest of the car is not set up for it.
Neither is better. They are different languages.
Strength and stiffness
Both finishes, when they are prepreg and properly cured, are strong enough for any cosmetic body panel or trim piece you would put them on. For the external pieces I make, front lips, diffusers, spoilers, mirror covers, grilles, skirts, the loads are modest compared to a chassis component. Either finish is more than up to it.
There is a real technical difference though. Twill weave has continuous fibres running in two directions, so it is highly directional in stiffness. That is useful for structural layups where load paths matter. Forged carbon, with its random tile orientation, has roughly the same strength in every direction. That is actually an advantage for complex three dimensional shapes like a diffuser fin or a grille slat, where the load is not lined up neatly in one direction. It is also why a lot of supercar manufacturers use forged carbon for suspension arms.
If you want the deeper dive on layup and why both forged and twill sit above wet layup carbon, have a read of dry carbon vs wet layup carbon fibre. And if you want to sanity check what you are looking at in person, our guide on real carbon fibre vs fake covers the tells.
Weight
In a part the size of a front lip or rear spoiler, the weight difference between forged and twill is small enough that you will not feel it, and a scale will barely see it either. Fibre density is similar, resin content is similar, laminate schedule does most of the talking. If you are buying carbon to shed kilos, focus on replacing bigger OEM pieces like bumpers or bonnets. The finish choice is not where the weight comes from.
Price
Forged carbon fabric itself costs more than standard twill prepreg, and the moulds for forged parts tend to need more care because the random pattern shows any surface flaw immediately. That said, once you factor in tooling, labour, clear coat, and the fact that every forged part is visually unique, the retail price on comparable parts usually comes out within the same ballpark.
In the current RB Innovations range, forged pieces usually are around 10% more than their twill counterparts.
How I'd pick between them
Here is my rough decision tree after doing this for a while.
- Go twill if your car is OEM or close to it, the factory parts already use twill, or you want the classic motorsport look. Twill also tends to age more predictably under UV because the pattern is more uniform.
- Go forged if you want the part to stand out, the shape is complex and organic (diffuser fins, grille surrounds, ducted lips), or you already have forged accents elsewhere on the car.
- Mix them carefully. I have seen builds pull off forged exterior with twill interior. It works when there is some breathing room between the two. What does not work is a forged mirror cover sitting next to a twill A pillar trim in the same line of sight.
One more thing. Twill variants are coming across more of our range after the current forged rollout. So if you love the look of a specific part but want it in twill, it is worth getting in touch. We keep an interest list for new finishes and it is the fastest way to hear when a twill version lands. Same goes if you are after a specific fitment we have not covered yet, the all makes and models page is a good first stop.
Care and longevity
Both finishes need the same care. UV is the enemy, not the fabric. A quality clear coat, a ceramic coat on top if you want to go further, and you will keep the piece looking fresh for years. Full breakdown in how to care for carbon fibre car parts.
FAQ
Is forged carbon real carbon fibre?
Yes. Forged carbon is a purpose-built prepreg carbon fabric with short irregular carbon tiles set in a random orientation, cured under heat and pressure. It is not chopped offcuts or shop scraps, it is a manufactured fabric designed for this exact process.
Is forged carbon stronger than twill?
Not universally, but it is more isotropic. Twill is stronger along its two fibre directions, forged is roughly equal in every direction. For most cosmetic car parts, both are comfortably strong enough.
Does forged carbon weigh more than twill?
No meaningful difference in a typical exterior panel. Both use similar fibre content and similar resin systems.
Will forged carbon look dated in a few years?
Unlikely. Forged has been on production supercars for well over a decade now and has become its own recognised finish rather than a trend. Twill has been around even longer and is not going anywhere either.
Can I mix forged and twill on the same car?
Yes, if you plan the separation. Keep one finish to the exterior and one to the interior, or pick zones where the two do not sit directly next to each other.
Which is easier to repair if it gets damaged?
Twill is slightly more forgiving because the weave pattern can be matched at a panel shop. Forged damage tends to need a full part replacement because the random pattern is impossible to blend. Budget accordingly if you daily your car.
Bottom line
There is no wrong answer. Twill is the classic, engineered, factory-correct option. Forged is the modern, unique, statement option. Both are real prepreg carbon fibre, both perform the same job on a car, and both will be part of the RB Innovations range going forward.
If you are stuck between the two for a specific part on your car, send through a photo of the build and I will tell you honestly what I think works. Browse the current range over on the full catalogue or get in touch if you have questions.