Normally I load the black and white png file into the 'convert image to 3d' add-in in simplify 3d. set the width I want it and it creates the stl file.
Usualy I use this for making keyrings with text files, and it's always worked perfectly.

But with this file all i get is a blank rectangle.
valscombsm.jpg

file above - it's a comb thought I'd have ago at scanning and printing.
It just won't extrude with s3d.
So is there any other easy way to turn this into a 3d file ?
Needs to be 2mm thick.
Although that's easy to change via slicer - so any thickness really. Dimensions of comb are 200x70mm
Just can't figure out why it's not working - same file type as I usually use, made from the same photo editing program. I've tried 2 colour & greyscale. I usually just go with the 2 colour b&W png.
This is weird.
Cheers