3DImka, who is being most of hidden-3d.com, is constantly pushing the boundaries of stereograms!

I highly recommend having a look at some of his best creations on deviant art [0], particularly his technic of matching outlines with the final 3d result [1], or his experiments with transparency [2].

[0]: https://www.deviantart.com/3dimka [1]: https://www.deviantart.com/3dimka/art/You-must-not-fool-your... [2]: https://www.deviantart.com/3dimka/art/8-Legs-Magical-Stereog...