Every panel layout starts with a handful of numbers: the panel size, the borders reserved for tooling, and the spacing between boards. The right values come from your fabricator, but you often need a starting point before that conversation happens. This page collects typical values from fabricators' published guidelines, and lists exactly what to request from your fabricator.
Panel rules are not one set of numbers per fabricator. They change with the depaneling method (V-score or tab-routing), with your board's thickness, process, material and layer count, and with whether the panel goes on to automated assembly. The same fabricator will quote different borders and spacing for a thin two-layer board than for a thick multilayer one based on their process and equipment capabilities.
| Parameter | Typical value | Notes |
|---|---|---|
| Production panel sizes | 18 x 24, 12 x 18, 9 x 12 in | 18 x 24 in is the most common. Sizes vary by fabricator, material, layer count and process. |
| Panel border (rails), typical | 0.5 to 1 in | Smaller borders are typically for double sided boards while multilayer boards require larger borders for lamination tooling. |
| Panel border (rails), minimum | 0.2 in (5 mm) | Some processes reserve more. Assembly needs rails on at least two opposing sides. |
| Board spacing, V-score | 0 in | Boards share the cut line. Routed features near the cut line can force spacing back in. |
| Board spacing, tab-routing | 0.063 to 0.1 in (1.6 to 2.5 mm) | The minimum between boards, set by the routing cutter the fabricator runs. |
| V-score cuts | Straight, edge to edge | V-score lines cross the full panel and suit rectangular outlines only. Minimum board size and thickness for V-scoring vary widely between fabricators. Using V-score generally means boards cannot be rotated on the panel. |
Values compiled from fabricators' published guidelines as of August 2026, linked in the references below. Fabricators update capabilities without notice, and your board's construction changes the answer. Your fabricator's numbers override every value on this page.
One small request to your fabricator, or to each fabricator you are comparing, gets you the values you need. Ask for their panelization guidelines for your board, and make sure the answer covers:
Use them in the free PCB panelization calculator: enter the panel size, border and spacing and see boards per panel and panel utilization for your board. Or if you have the full KwickFit product, add them to your configuration, so you enter them once and use them for all future layouts.
It's important to get the information early in the design process so you can make adjustments that impact board price. See where panel optimization fits in the design flow for guidance.
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The values above were compiled from these published fabricator guidelines. They are linked for reference, not as a recommendation of any fabricator, and each fabricator's current pages are the authority on its own rules.
Related: how to fit more boards per panel covers the levers these numbers feed, where panel optimization fits in the design flow shows when to collect them, and The PCB Cost Cliff shows what the layout decision is worth in real dollars.