Color is the first thing a customer notices and the hardest thing to hold. Two batches can pass every dimensional test and still be a commercial failure because the second order does not match the first.
What ΔE measures
ΔE is the calculated color difference between a sample and a reference in a defined color space. Lower is closer:
| ΔE (typical) | What a customer perceives |
|---|---|
| < 1.0 | Practically identical in most lighting; suitable for adjacent parts in one assembly |
| 1.0 – 1.5 | Very close; visible side by side to a trained eye, acceptable for most products |
| 1.5 – 3.0 | Noticeable difference; a repeat order may be rejected by a retail customer |
| > 3.0 | Clearly a different color; a batch mismatch claim |
ΔE ≤ 1.5 between batches is a common working limit for filament sold under a brand, and it is what VOXFIL publishes for its standard range.
Why color drifts
- Masterbatch dosing variation — manual dosing drifts; gravimetric dosing holds.
- Pigment lot differences — the same color code from a different pigment lot can shift.
- Process temperature — some pigments are heat-sensitive and shift with extrusion temperature.
- Polymer carrier differences — the same masterbatch in PLA and PETG does not give the same result.
- Measurement conditions — different light sources or instruments produce different numbers, so the reference method matters.
What to write into the specification
- Color reference and how it was agreed: Pantone, RAL, hex, or a physical retained sample
- ΔE limit between batches, and the instrument/illuminant used to measure it
- Whether the limit applies to the masterbatch, the filament, or a printed plaque
- Color hold: does the factory retain pigment and formula so repeat orders match?
- Sampling procedure: what you receive for approval before a production run
For brands selling color ranges
- Standardise on fewer masterbatch families. A tight palette is easier to hold than 40 distinct pigments.
- Photograph under fixed light. Consistent product photography is part of color perception, especially online.
- Retain a reference plaque from each approved color so a future dispute has a physical benchmark.
- Ask for the ΔE history on repeat runs — a stable trend is more valuable than a single good result.
VOXFIL runs gravimetric masterbatch dosing, holds color formulas on file for repeat orders, and works to ΔE ≤ 1.5 across batches on its standard range. See the color range or start a custom color program.
Frequently asked questions
What does ΔE 1.5 mean for filament color?
It is the maximum calculated color difference between batches. At ΔE ≤ 1.5 a repeat order is very close to the original — visible side by side to a trained eye but acceptable for most branded products.
Why does my repeat filament order not match the first one?
Common causes are masterbatch dosing variation, a different pigment lot, extrusion temperature differences, or a changed formulation. Ask the supplier whether color formulas and pigment lots are held on file for repeat runs.
How should I specify color in a filament purchase order?
State the color reference and how it was agreed, the ΔE limit between batches, the measurement instrument and illuminant, whether the limit applies to filament or a printed plaque, and whether the factory holds the formula for reorders.