 So I showed you how to slap materials onto a simple baked object with no IDs but you want to know how to use materials on objects that have IDs. Not a problem. The simplest way to do this from Blender is to just UV unwrap your object, then open the image editor, create a new image, then open the shader editor, shift A, S, image, select the image that you just created and drag it into the base color. Go into edit mode, select all the phases you want to group together by material, then go to texture paint mode, select the paint bucket, have selection turned on, pick any generic color you want to designate the group and left click to apply it. Now I want to have three different materials so I'm going to separate my IDs into red, green and blue. When I'm done I'm going to save the new texture map as a PNG image, then I'll export the object as an OBJ. Now from here in substance, under file, new, just import your object the same way you normally would but this time since we already UV unwrapped it in Blender we don't need to auto unwrap it here in substance and as usual we'll bake our mesh maps but this time we'll keep IDs on. Now to add our map go to file, import resources, add resources, find your map and specify it as a texture. Add it to your current project, import and then under texture settings and ID set it to your ID map you created from Blender and since I have three different color IDs I'm going to just pick three different materials so I'll just pick yellow paint, gold and this dark steel looking one and now under layers you match the materials based on the color ID by right clicking, add mask by color selection and now if we go down here under pick color whatever color I click on is the area that the dark steel material is going to get applied to so if I click on green that is exactly where the dark steel gets applied and we just repeat this process for the rest of the materials so again right click, add mask by color selection, pick color and when I hit blue the gold material is only applied to the blue areas and of course if you right click the yellow paint material, mask by color selection, pick color and if I hit red that is where the yellow paint gets applied, you're done. Now for those of you wondering why this is useful the reason is it allows you to clearly designate different materials into a single 3d object. A lot of beginners make the mistake of just separating everything they expect to be different materials into different objects but it's actually much easier to keep things organized with texture IDs so I hope that clears things up and as always hope you have a fantastic day and I'll see you around.