Gerber Files Explained: How to Export, Send & What Manufacturers Need

Published June 10, 2026 · By Mayio Engineering Team · 7 min read

Gerber files are the universal language of PCB manufacturing. Every factory in the world — from Shenzhen to Germany to Ohio — reads the same format. If you can export Gerbers, you can get your board made anywhere.

What Are Gerber Files?

Gerber files describe each layer of your PCB as a separate image. Think of them like X-ray slices — one file for the top copper, one for bottom copper, one for silkscreen, one for solder mask, and so on.

What Files You Need to Send

File	What It Describes	Required?
Top Copper (.gtl)	Top copper traces and pads	✅ Yes
Bottom Copper (.gbl)	Bottom copper traces and pads	✅ Yes (2-layer+)
Solder Mask Top (.gts)	Where solder mask is removed	✅ Yes
Solder Mask Bottom (.gbs)	Bottom solder mask openings	✅ Yes (2-layer+)
Silkscreen Top (.gto)	Component labels, logos	✅ Yes
Silkscreen Bottom (.gbo)	Bottom silkscreen	Optional
Paste Top (.gtp)	Solder paste stencil	For assembly
Paste Bottom (.gbp)	Bottom paste stencil	For assembly
Drill (.drl)	Hole positions and sizes	✅ Yes
Board Outline (.gko)	Board edge cuts	✅ Yes

How to Export from Popular EDA Tools

KiCad

Open your PCB layout
File → Fabrication Outputs → Gerbers (.gbr)
Select all layers you need
Then: File → Fabrication Outputs → Drill Files (.drl)
Zip everything into one file

Eagle

File → CAM Processor
Select "gerber" from the job dropdown
Process Job → save all files
Zip into one file

Altium Designer

File → Fabrication Outputs → Gerber Files
Set units and format (mm, 4:4 is standard)
Select all layers
Run → then File → Fabrication Outputs → NC Drill Files
Zip everything

EasyEDA

File → PCB Fabrication File (Gerber)
Download the zip directly
Ready to send

Common Mistakes

1. Sending Screenshots Instead of Gerbers

A screenshot of your PCB layout in your EDA tool is not a Gerber file. The factory cannot manufacture from a screenshot. Always export properly.

2. Missing Drill File Units

If your Gerber is in mm but your drill file is in mils, the holes will be 25.4× too far apart (or too close). Always check: File → Drill Setup → Units should match your Gerber units.

3. No Board Outline

If the factory can't see where to cut, they'll ask. This adds a day. Make sure your Edge.Cuts layer is exported.

4. Forgetting Inner Layers (4+ Layer)

For 4-layer boards, you need inner copper layers (.gl2, .gl3). Missing these means the factory has to guess your stackup.

5. Not Zipping Everything

Send one zip file with all Gerbers + drill files. Not individual files. Not a RAR. One .zip.

Pro tip: Before sending to the manufacturer, open your Gerber zip in a free viewer like [Gerber Viewer](https://www.gerber-viewer.com/) or the Ucamco reference viewer. Visually confirm all layers are present and look correct.

What Your Manufacturer Does With Them

Import & Parse — Load all Gerber layers into their CAM software
DFM Check — Run design for manufacturability checks
Panelization — Arrange boards on a manufacturing panel for efficiency
Generate Phototooling — Create the masks used to etch copper
Quote — Calculate pricing based on layer count, size, quantity, and specs

Ready to Get a Quote?

Send your Gerber zip files to us. We'll review them by hand, provide a quote within 24 hours, and flag any issues before production starts.

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