Recently I showed some hyperbolic planes in my project list. I worked another and made some pictures of the development.

Guess how many stitches I worked in the last round when I started with 12 sts and double every 6th stitch.
I’ll give you a hint: I needed 3.5 hours for the last round :-)

You may want to have a look at my video Red Hyperbolic Pseudosphere on youtube.

And here the video with Daina Taimina presenting crocheted hyperbolic planes