You can texture a 3D model without Blender using tools like Substance Painter, GIMP, or online platforms such as Tinkercad or Sketchfab’s Texture Editor.
These tools let you apply, paint, or adjust textures—beginners might prefer drag-and-drop options (like Tinkercad for 3D prints), while advanced users can use Substance Painter for realistic material layers.
For new users, try free online tools: Photopea (to edit texture images) and Windows 3D Viewer (to preview). They’re easy to use and don’t require downloads.