Upload texture normally and put in the texture tab in Second Life. Texture will map on the sculpted prim surface exactly the same as you see in Blender. Read this tutorial..
Blender Texturing Technique
September 13th, 2009
Blender Texturing Technique
Texturing technique is playing an important part in Second Life and Opensim creation since we have only color texture available. You will need ability to simulate realistic refraction and shadow and paint into single color texture.
Texturing Sculpty in Blender 3D texture paint mode and with 2D image editor.
Learn to do a Quick, Fast and Easy Painting with Vertex Paint tools.
