Let’s first clarify a common confusion: “Bio-based dyes” ≠ traditional “plant dyes.” The former are produced via synthetic biology / microbial fermentation / molecular modification (their structures can still be precisely designed), while the latter are directly extracted natural pigments (often dull, prone to fading, and require heavy metal mordants). The performance comparison should be based on bio-based vs. petroleum-based synthetic dyes. Below is a breakdown by indicator.
Several Points Often Obscured by Marketing Language
① “High exhaustion rate” ≠ “high fixation rate” – depends on dye type
- For anthraquinone acid dyes (wool), bio-based exhaustion can reach 97.5%, but for humic-acid-based reactive dyes, fixation is only 70% – similar to conventional reactive dyes. This is because the reactive group (chlorotriazine) is the same; bio-based modifies the parent structure, not the fixation mechanism.
- The bacterial dyeing route (Colorifix/Newera) achieves >95% fixation because the bacteria produce pigment directly on the fiber + fix it in situ – a different pathway, so this number cannot be applied to all bio-based dyes.
② Color spectrum is currently the real industrial bottleneck
- Conventional synthetic dyes adjust chromophores (azo, anthraquinone, phthalocyanine, etc.) to cover almost any wavelength. Bio-based relies on microbial metabolism + plant extraction. Bright blue, bright green, high-saturation purple – these high-saturation cool colors are still difficult to produce stably. Engineering strains to modify metabolic pathways for broader color range is still in progress. So the current focus of bio-based is mainly on earth tones, indigo, monascus red, spirulina blue, plus black (carbon black/modified routes).
③ Cost inversion is due to “downstream” processing
- Bio-based dyes generally sell at 15–50% higher prices than conventional ones. Interestingly, however – Innova Microbial Indigo has already reached 35,000 RMB/ton vs. chemical synthesis 50,000 RMB/ton, 30% lower – this is an exception (scale + glucose feedstock + 99.9% purity). The general case of bio-based dyes is still more expensive because separation and purification account for 50% of production cost; fermentation itself is not that expensive. Colorifix’s unit cost is still 30% higher than synthetic. So “bio-based is always expensive” is wrong; “most are still expensive today” is correct.
④ The old impression of “plant dyes = dull and fading” has been broken by molecular modification
Companies like Lexus, Yida take natural pigments / biosynthetic pigments to perform molecular structure modification + grafting reactive groups, achieving color fastness of grade 4–5 and expanding the color palette to four-season shades. This is no longer the same thing as traditional plant dyes. If someone uses “poor performance of plant dyes” to dismiss bio-based dyes, they are conflating concepts.
Decision-Making Guidance
- Premium / export / baby & children / sportswear brands: Bio-based performance is already sufficient, and compliance benefits (REACH, OEKO-TEX 2026, revised GB 30981) are a bigger driver. Even if the unit price is 15–30% higher, brands are willing to buy.
- Bulk commodity / high-saturation bright colors / full-spectrum quick-response orders: Conventional synthetics still dominate; bio-based color spectrum and cost advantage have not yet arrived.
- Indigo (denim) is a special track – microbial indigo has 99.9% purity with cost already inverted and wastewater -95%. It is the category closest to large-scale replacement of conventional dyes among all bio-based dyes.
