Actually, Vially is wrong. Any MAT file with a full path is rejected during store testing. All MAT files are to be configured with :Runtime:textures:etc . This may happen in freestuff, but not store items. For starters, what MAT files are you trying to use? You can only use files designed to be used on Victoria - such as second skins and skin textures. MAT files that load clothing textures are designed to be used on specific clothing. You also have Victoria 1/2 and Victoria 3, each with different mapping so that second skins and textures designed for V1/2 cannot be used on V3. For a beginners quickie guide: Load Victoria (3 in this example) and make sure a body part is selected. Go to the Pose folder and browse to where the mat was installed. Click on the MAT you wish to apply, then click the tick at the bottom of the menu. That's it. Your mat should now be applied.