Handing over source files for a Commission discussion

[Jaxilon]

I have been working on a requested commission and the question came up regarding source files. I use Gimp so that would be the .xcf which includes all the layers etc. I guess Photoshop equivalent is the .psd file.

I talked to a couple of you already but my client had never really thought about this as being any sort of issue. He hadn't thought about them as ultimate proof of authorship so we were both curious to hear what the rest of the community had to say.

The reason the request was made for the source file is so the map could be updated to reflect changes in the world as they campaign in it for the next couple years.

So, for the record, how is this handled?

Hopefully, that made sense.

PS. I am learning here as well because had I thought about it beforehand we would have already discussed this.