Difference between F.Fab and F.Silks?


Now I’m going to make PCB artwork.
there are two layers (fab, silk) which have reference number and value.

I’m curious that I need both of them when I make gerber?
or just need silk layer?

sorry for poor English, thanks

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There is no layer called a “Fab” layer on an actual PCB.

For the PCB the important fabrication layers to enable are as follows:

Edge.Cuts (which contains the board outline)


No problem. Your English is way better than my Korean. (I can recognize Korean characters, and that is about it.) :wink:

@Sprig has the list you need.

Don’t forget to also include the drill file (usually Excellon, not Gerber). Some manufacturers want two files, one for NPTH holes and one for PTH holes. Other manufacturers want both types of holes in one file. Check with your manufacturer.

If you need to get a solder paste mask made, also generate the F.Paste and B.Paste layers (depending on which layers have SMT pads). But you may need to send these files out to another fabrication service.

For the layers, double check the FAQ entry about what the layers are.


this is excellent answer.
Thanks Sprig :slight_smile:

I think I need to study about NPTH and PTH
and I didn’t know about Excellon format before you mentioned it.

Thanks SembazuruCDE :slight_smile:

I’ve got into that problem once. May be it will be halpful.
About 20 years ago we agreed with PCB manufacturer about how to specify drill holes. Those time there were no speak about possibility of using separate files for NPTH and PTH.
Our agreement was that except the drill file we just give the text file clearly saying what tool number in file means what drill tool to use. So I have written a simple program to generate that text file. The text file was saying for example:
T01 - whole 0.5 mm, drill 0.6mm.
T02 - …
difference betwean whole size and drill always was 0,1mm.

In Protel (old one, I don’t know how is in nevers) when I put the 0,5mm whole at copper or out of copper that both of them are assigned (in drill file) the same tool for boring - so (those times) it just had to be drilled with the same drill.
And it worked well for 20 years, not only with that manufacturer, but also with our contract manufacturer who gaved our PCBs to severeal PCB fabs.

But 1.5 year ago it happened that I used 0.5mm at copper and out of copper (assuming that both are drilled with 0.6mm so I have 0.5 mm hole at copper and 0.6mm hole out of copper) and when we got 5 prototype PCBs we found that we can’t put the optical fiber over the LEDs because the wholes are 0.5mm instead 0.6mm (0.6 was the size that those optical fiber had to be put with some force and stayed at place).
I asked PCB manufacturer what have happened - they just overlooked our text file. They said to send them these PCBs back just to make these wholes bigger. But we had no time and drilled them ourself with some bigger drill (I think 0.8mm) with the effect that we had use glue to our optical fibers.

That way I found that now they have the software that compares drill file with gerbers and recognises at PCB when the same tool number in drill file is used at copper and out of copper and just uses not the same but separate tools and it is their standard way of work now.
Since then we don’t give them our text file and I don’t use the 0.5mm hole when I really need 0.6mm, as I was doing in past.


Check with the company that you plan on using to make your boards. They might have instructions for how to export gerbers from KiCad in a format that they accept. Every manufacturer is a little different. I just did a google search on “kicad export gerber” and found several manufacturers’ KiCad specific pages. Regarding my note about NPTH and PTH drill files, Seeed Studio specifically says to merge the two:

We suggest you select the option to Merge PTH and NPTH holes into one file, otherwise KiCad will separate plated and non-plated holes into two drill files, and if one is missing, there will be holes missing on your boards.

But JLCPCB isn’t very clear, but they seem to indicate not merging the files. This is one example of many of different export options.

If you aren’t sure who you want to use to make your boards, check out this site to get quotes from many large PCB manufacturers:

Once you decide on a board manufacturer (or change to a different manufacturer), make sure your boards are manufacturable by the new company. Check the new manufacturer’s minimum spacing, copper width, and drill size against your board.

If you have any specific questions about what settings to use for a specific manufacturer when generating gerbers and drill files, make use of their customer support. The want to take your money so they should be able to answer your specific questions about their processes. (We here on the forums don’t know all the details about every manufacturer as we are just users like you.)


Thanks for telling me your experience
now actually I use only 0.4mm drill holes
but your experience will be really helpful :slight_smile:


Wow… you give me amazing information…
Thanks for sharing

now I use only PTH, so I don’t worry about options
Thanks again

These days the industry is pretty standard that the hole diameter is the finished size.


I appreciate your enthusiasm for KiCad and I saw your avatar popping up a lot lately.
You have created 23 topics in 24 days, and a lot of them are with very simple and basic questions.

Because of this I even stopped from reading them. As with probably a lot of other people here, we like to help, but time ticks on and is not stretchable nor reversible, and therefore I try to limit myself to more intesting topics or where people really get stuck on a feature, (even if it’s a simple one).

It may be time for you to spend a little less time on posting and a bit more on reading the manuals.

A few pointers for asking questions over public media:


Hi, paulvdh
Thanks for your support. I know you because you’ve left comment for me many times.
and I agree with your words
actually I read maybe half of manual (I’ve download all manual in my PC). and tried to read and understand
but for me English is like a wall, that’s the reason I asked and posted many basic questions
and I also watched almost everyday Youtube about kicad to learn it.
yesterday, I ordered my first PCB and now I think It’s time to read manual and search everything related to Kicad and Circuits and PCB and etc. before posting

Thanks for your advice and supports again
take cares :smiley:


Just remember, your English is better than my Korean. I hope all of our answers were helpful and understandable.

Congratulations. I hope it turns out well for you. If there are any errors, I hope you can learn from them.


Haha Thanks SembazuruCDE
you are right, I can have more confident now.
Let’s keep learning and making

Take care :smile:


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