PCB material layers & sizing
The three fixed PCB material layers and the fixed panel dimensions zpd designs against.
Three fixed material layers
A zpd panel is a real PCB, and its visual "colors" represent fabrication materials rather than arbitrary UI paint. Every panel uses the same three fixed layers:
| PCB material layer | Display/fabrication appearance |
|---|---|
| Copper | Gold, representing exposed copper with the product's HASL surface finish |
| Solder mask | Black coverage above copper, opened wherever mask artwork is drawn |
| Silkscreen | White printing at the top |
These material roles are fixed—there is no fourth material or custom-color mode. The three legacy color indexes remain a display and import-compatibility mapping; see Material stack and display colors for the exact values used in the editor.
Fixed material stack
The physical board is built bottom to top: Copper → Solder mask → Silkscreen. The Layers UI intentionally reads in the opposite visual direction, top to bottom: Silkscreen → Solder mask → Copper.
Those three entries are fixed containers, not ordinary groups. They cannot be renamed, deleted, grouped, selected, or reordered. Ordinary nested groups still work inside a container, and moving artwork between containers changes its effective material. Copper is the requested gold/HASL finish, Solder mask is black, and Silkscreen is white—even if imported legacy children carry a misleading color field.
Solder-mask artwork is inverted: a drawn mask shape is an opening where the mask is removed, exposing the copper below—or the bare FR4 substrate wherever no copper lies under that opening. The panel's black is the mask sheet itself, so an empty but visible Solder mask container is full coverage, while hiding the container means no mask anywhere. A hole in an even-odd path is a hole in the opening, so that area keeps its mask.
Info
This material model is what the Gerber export writes. Download Gerber (.zip) emits .GTL (copper), .GTS (solder mask, declared with negative file polarity), .GTO (silkscreen), and .GKO (board outline profile), plus a README.txt. It is artwork only—no Excellon drill file and no mounting-hole geometry—so it describes artwork for an already-specified Takazudo blank panel, not a standalone orderable board. One known limitation (issue #218): the current boolean backend corrupts the union for many built-in pattern generators (36 of 62 at the last measurement), and the exporter refuses those layers instead of emitting geometry known to be wrong.
Panel width: HP
Panel width is specified in HP, the Eurorack-style horizontal-pitch unit. zpd does not compute width as a simple HP * 5.08mm multiple — real Takazudo Modular panels are undersized against that nominal pitch for mounting clearance, so each supported HP has its own measured width. See Panel sizing for the full width table.
Panel height: fixed at 3U
Panel height is not configurable — every panel is 128.5 mm, the fixed 3U Eurorack panel height. There is no height field in the editor because there is nothing to choose.
Info
Width (via HP) and height (fixed) together define the panel's fabrication bounding box. Layers are free-form within that box, but the box itself is never a design choice — it is Takazudo Modular's product spec.