How can i clear a picture and only see my sketch

[Anonymous]

I imported a picture. Then created a new slide and drew a sketch on the picture. 

How can i see the sketch without the picture ?

now the only way is to totally clear the picture making it disappear completely

but i wanna keep the pic in the original slide and see the sketch alone in another slide  

[david.lau]

1. Import the image on 1 layer.
2. Add a new layer and work on that layer. 
3. Go back to the image layer and adjust transparency as necessary to see your sketch.

See:

http://help.autodesk.com/view/SKETPRO/ENU/?guid=SKETPRO_Help_sb_layers_add_layers_html