Create a sketch on the XY plane and sketch the diameter of the desired lampshade size
Make a small cut on the cylinder which will be use for unfolding the cylinder later.
After extruding the sketch except for the small cut, extrude a small distance in between the gaps the cylindrical first before convert model to sheet metal in order to unfold.
Unfold cylinders
Under Sheet metal tab, moust over modify and select "unfold".
Select the extruded side (highlighted in blue) as "Stationary Entity" and the circumference of the cylinder as "Bends" to unfold whoch result in a rectangle.
Next, create sketch on the rectangle (aware of which side surface using, it could be internal circumference of external one)
Now starts to design any desired design on the sketch (whether include canvas to design or manual design)
When all deisgn is complete, extrude the sketch by 1mm
Lastly, at toolbar, select "Refold Faces" to return back to cylinder which all design extrusion made will also be surrounding the model.
