Makeup and Skin

SOFTWARE

Programs with a * are the most used by the community

For extracting textures:

You can also use raw png textures from the body devkits if you find them in resources sections on modding sites and discord servers

For painting (Diffuse/Base):

The Diffuse/Base now stores transparency information in its alpha channel. If you wish to paint on it as a PNG in any art program you like just make sure to save your alpha layer so you can add it back when you’re done

For painting (Diffuse/Base) on a 3D Model:

Substance is the most versatile of these programs, but it is also the most complex. There is a bit of a learning curve for first-timers. Learning the basics first is highly recommended

While Blender is capable of painting on 3D models it can feel very limited if you’re not experienced with that aspect of the program so it goes mostly unused by modders

For adding 3D details (Normal Map):

Normal map information requires software that can edit and save its different channels (RGBA). Not any program and format can do this. Photoshop itself requires an external Plugin in order to open and save DDS files

GIMP is often recommended as an alternative to Photoshop but its UI is a nightmare and most guides are made with Photoshop in mind, which causes many compatibility issues. Photopea is a better alternative, but in order to keep the quality of your DDS you will need to export it as a PNG and then convert it into a DDS

In my experience, while alternatives to Adobe programs are valid, they can be a bit of a pain to use when it comes to following guides. If you insist on using other type of software please take a look at this detailed graph first to inform your decision better.