Blender to Sculptris

Im trying to export a obj from blender, so i can use it in sculptris.
but when i open it in sculptris, its like it make it transparant,on the mesh facing towards me, and when i sculp, it only affects the backside.
Can anybody tell me what is wrong ?

Usually, it’s because there are inverted normals in your model.
In Blender, before exporting your model into OBJ format you have several methods to see if you have inverted normals :

1st one , in Object Mode set your model Shading to “Smooth”, if you see some strangely placed very dark parts, you’ve got some normals not correctly oriented.
2nd one , in Object Mode, instead of Solid display, set Textured Display , you should see where the faces are inverted
3rd one , go to Texture Painting mode and you’ll see “holes” , they’re were the faces are inverted.

To fix : select the whole model in Edit Mode and press CTRL+N (or Mesh -> Normals -> Recalculate Outside)
If it does not fix the whole model, select the individual faces that have inverted normals and press Mesh -> Normals -> Flip Normals

Once the model do not have anymore any inverted normals, you can export it into OBJ format.