I learned how to make liveries awhile ago and I am self taught. I know there are educated graphic designers out there and there are also other self taught designers. Sometimes you're looking for a livery, or squadron that wasn't included in the OEM package that you bought or downloaded and you want to make your own and once you are done making the overall texture file you load it in and notice shadows of the former design. Maybe you'll see shadows where insignias once were, or text and it just looks ugly. So this is usually due to a second layer file with the same name but in MSFS 2020 its usually labeled "COMP" ands it's a "roghmet" file used for lighting.
In the screenshot I'm suing the main image texture has a blue circle and the roughmet has a red circle.
Without both you get a dark 3D textured model, and it really doesn't look as nice as a livery that someone else will do and post here. The main problem for us non-Adobe users is opening the roughmet file. So you are forced to create your own. I've watched tutorials using Adobe Creative Suite and some of us don't like or want to use Adobe so we use Gimp or other really good programs like Clip Studio Paint. The problem is making the roughmet file. In Adobe you can take your main image file, select a filter click a button and voila there is your roughmet, save it and put it in the directory, and you're done. For the rest of us we need to do it manually and make sure the blues reds greens yellows are in the right places to perform the proper task (price of doing it for free or less).
So does anyone else here use GIMP, have the DDS extension and are able to open any roughmet file and edit it? If so would you care to share with the rest of us how to do it? I still have some issues where a .DDS file can't be opened. So again I'll sit down and make my own. However tips and tricks on how to do this without paying for photoshop would be great for all of us.
Simple tutorial for DCS which also applies to Microsoft Flight Simulator 2020 ( is the same for anyone who wants to start texturing.) https://www.airgoons.com/w/How_To_Make_A_DCS_Livery