ADR-029: Brand Palette & Visual Identity

Status

Accepted

Context

Every successful open-source printer project has a recognizable visual identity:

Project Signature Color Character
Voron Red/Black Aggressive, performance
Prusa Orange Friendly, approachable
Bambu Green Modern, consumer
RatRig Blue Engineering, premium
Ender Blue/Black Budget, utilitarian

Amalgam needed a palette that: 1. Reflects the “Tractor” philosophy — industrial, heavy, utilitarian 2. Uses the cheapest available filaments — no specialty colors 3. Works with a single filament swap — no MMU or multi-color hardware 4. Distinguishes from every competitor — no red, orange, green, or blue

Grey is the one color no other printer project owns. Cast iron, concrete, industrial machinery — all grey. It’s the tractor color.

The Filament-Swap Logo Problem

Most printer projects either: - Print in one color (boring, anonymous) - Require multi-material hardware for branding (expensive, fragile) - Apply stickers or paint (cheap-looking, peels off)

A raised logo pad (0.5mm above the surface) enables a single filament swap at one layer — pause, swap to white, print 2-3 layers, swap back. No MMU needed. The logo is literally part of the geometry.

Texture as Identity

Layer lines are the fingerprint of FDM printing. Rather than hiding them (impossible on a scavenger printer), fuzzy skin turns them into a feature — an intentional industrial texture that: - Hides layer line imperfections (forgiving on a scavenger build) - Adds grip on assembly surfaces - Creates a distinctive “cast iron” finish that reinforces the tractor aesthetic

Decision

Three-Color Brand Palette

Role Color Hex Material
Body Dark Grey #4A4A4A PLA+/PETG filament — all printed parts
Accent White #FFFFFF PLA filament — logo pads (filament swap)
Base Near-Black #1A1A1A Paint (MDF base), anodized aluminum (extrusions)

Hardware (Silver, #C0C0C0) is documented for reference but not configurable — bolts, rods, and bearings are whatever color they come in.

Visual Hierarchy

Black base + frame  →  disappears, anchors the build
Grey printed parts  →  focal point, structural, industrial
White logo accents  →  branding detail, high contrast against grey
Silver hardware     →  functional, not decorative

Implementation

All palette values live in cad/config.py Section 11 as the single source of truth:

BRAND_BODY_COLOR = "#4A4A4A"
BRAND_ACCENT_COLOR = "#FFFFFF"
BRAND_BASE_COLOR = "#1A1A1A"

These propagate to: - CAD exports — glTF and 3MF models render in brand body color - Documentation — Quarto variables via scripts/export_config.py - Website — CSS custom properties in docs/index.html - Brand module — amalgam/lib/brand.py provides build123d Color objects

Logo Pads

Optional raised geometry on printed parts for filament-swap branding:

LOGO_PAD_ENABLED = True      # Set False for plain parts
LOGO_PAD_DIAMETER = 18.0     # mm across flats
LOGO_PAD_HEIGHT = 0.5        # mm raised (2-3 print layers)
  • When enabled, structural parts get a small Amalgam octagon+A mark
  • The pad is just geometry — the color change is a slicer operation (M600 pause)
  • Parts are structurally identical with or without pads
  • Applied via amalgam/lib/logo_pad.py, not baked into structural geometry

Fuzzy Skin (Texture Recommendation)

Documented but not enforced by geometry — this is slicer configuration:

FUZZY_SKIN_RECOMMENDED = True
FUZZY_SKIN_POINT_DISTANCE = 0.3   # mm
FUZZY_SKIN_THICKNESS = 0.2        # mm

Apply to cosmetic outer faces only. Never on mating surfaces, rod channels, or bearing seats.

Consequences

Benefits

  1. Zero added cost — Grey and white are the cheapest filaments available
  2. No special hardware — Single filament swap, no MMU
  3. Distinctive identity — Grey + white logo is unique in the 3D printer space
  4. Forgiving finish — Fuzzy skin hides imperfections on scavenger builds
  5. Fully optional — LOGO_PAD_ENABLED = False for plain parts; any filament color works
  6. Single source of truth — Palette in config.py feeds all outputs automatically

Trade-offs

  1. Grey doesn’t photograph well — Dark grey on dark background needs good lighting for glamour shots
  2. Filament swap is manual — Requires operator attention at the pause layer
  3. Fuzzy skin adds print time — Marginal (~5-10%) but nonzero
  4. Grey is polarizing — Some builders will want color; the config allows it but brand docs show grey

What This Means for Builders

  • Following the brand palette: Buy dark grey PLA+ and a small amount of white PLA. Paint MDF base matte black. Optionally enable fuzzy skin on cosmetic faces.
  • Ignoring the brand palette: Set LOGO_PAD_ENABLED = False, print in whatever color you like. Parts are structurally identical.
  • Customizing: Change BRAND_BODY_COLOR in config.py. The logo pad and exports will adapt. The palette is a recommendation, not a constraint.

BOM Implications

Brand-Compliant Build

Item Purpose Cost (AUD)
Dark grey PLA+ (1kg) All printed parts $18-25
White PLA (small amount) Logo pad color swaps $0 (leftover scraps work)
Matte black spray paint MDF base $8-12
220 grit sandpaper MDF prep $3-5

Additional cost for brand compliance: ~$10-15 (paint + sandpaper; filament is needed regardless).

Plain Build

No additional cost. Print in any color. Skip logo pads. Leave MDF natural or paint any color.

References

  • ADR-028: Target Filament Selection (PLA/PETG/TPU as primary filaments)
  • ADR-000: Engineering Philosophy (“Tractor” aesthetic)
  • cad/config.py Section 11: Brand & Cosmetics configuration
  • cad/amalgam/lib/brand.py: Palette constants and Color helpers
  • cad/amalgam/lib/logo_pad.py: Logo pad application library
  • docs/guides/print-settings.qmd: Print settings and brand guide