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


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.

Calculating Cost

You’re billed for the smallest rectangle that would enclose your design, so if you have a square or rectangular board, it’s just the length times width. A circular board with a diameter of 2 square inches would be billed the same as a 2”x2” square. An L shaped board would be treated as though it were “filled in” to a solid rectangle.

We round down to the thousandth of an inch, so a 3.141592 x 2.71828 inch board would be 8.539 square inches.

Cutouts and Slots

Internal outlines are generated in a similar way to the board outline, but with additional requirements. You can read more about those at our Internal Cutouts and Slots guide.

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 inside the board are indicated in a similar manner. The Internal Cutouts and Slots guide has additional information pertaining to internal slots.