Board Outline

Our service requires a board outline gerber, which indicates to us and the fab where the edge of your board is to be located. This layer is used by our service to generate the billing cost based on your board area, as well as enabling us to remove data that lies outside your board to avoid affecting adjacent designs. The fab also uses this outline to determine how to cut your board out from the panel.

While most design tools make producing this layer fairly straightforward, some design tools include additional data that causes issues, or fail to generate it at all. If our system rejects your board due to outline or size issues, try going through our outline troubleshooting guide, or contacting our support staff at [email protected]


The smallest dimension of your board can’t be smaller than 0.25 inches. The smallest board you can make is 0.25 inches by 0.25 inches.

The largest dimension you can have is 16” by 22” inches.

Board Outline Preview Images

This is a good Board Top preview with top copper, mask, silk, and outline.

This is how the Board Outline preview should look.

Fab interpretation

The following image indicates how the fab interprets the data from your board outline layer. We recommend a small but nonzero line width; the fab will route so the edge of your board is at the center of your line, no matter how wide it is.

How the fab will route the outline.

Cutouts and Slots

The board outline is also used to indicate cutouts and slots. Cutouts inside the board are indicated in a similar manner to the board outline. Smaller slots have additional requirements, which you can read at our Internal Cutouts and Slots guide.

Calculating PCB Size

The size of a PCB is determined by the smallest rectangle that will enclose the design. Arbitrary board shapes are allowed, but will be billed as if they were a rectangle, as shown below.

Examples of boards with the area used for billing

PCB areas are rounded to the nearest thousandth of an inch.

If a board size or shape seem incorrect, see the outline issues page for more information.