Blurry texture after baking


this may be a noob question but I started baking my materials of each mesh (or multiple) into one single material for performance reasons. Let’s say I have a mesh (e.g. a box) with 4 materials. Three materials are just some basic colors (with base color and metallic and roughness) and another is an image texture of size 512x512 (for example a label with some small text).

When I then use the Merge Actors tool in the UE developer tools and merge the materials of the box, the label becomes very blurry and the small text totally unreadable. Obviously I can increase the overall material texture size in the Merge Actors settings panel significantly (even 1024x1024 wasn’t enough to make it readable) but then it would apply this size on all its textures. I don’t think those other 3 materials actually need this texture size and it could make my merged material (and its textures) too high res for its purpose.

How can I ensure this one material/texture - the label - keeps its sharpness (resolution) while not having a significantly high size for all my textures of my merged mesh? What’s a good practice in this case?

Thanks in advance for your suggestions.