Freestyle objcet invisible

hi there,
is it possible to make a object completely invisible and just render the lines with freestyle? I tried a transparent material, but there are strange effects like blue lines.


Yes it is. Turn off solid from render layer the freestyle lines are on. Background can also be made transparent by unchecking sky on it, or by switching alpha to transparent in render properties -> shading.

Another way to do it is to:

!-Select the object in question and go to the materials tab.
@-Change the material type from ‘surface’ to ‘Volume’
#-Go down to thew ‘Density’ section and change both Density values to ‘0’