I remember, in my school days when comics were a rage among kids.
local brands like Diamond comics, Manoj comics and Raj comics published 6-8 titles every month which used to be called a set. there were our regular book corners which used to rent it out on 25 or 50 paise per comic book.
they sometimes came up with special issue which were publicized as 3D comics. these comics were packed in a fancy wrapping and were provided with a spectacles which had red and blue coloured lenses. It never became popular but had a novelty value to it
recently, I visited raj comics website. they had changed it's layout and improved it visually.
there, I found some links to 3D comics download.
3D comic covers on Raj comics website