The Origami Forum

I am using the book Works of Satoshi Kamiya (which has very good models by the way) and I am a bit stumped on steps 18-21. It's some sink that I don't quite understand. I was wondering if anyone could help me out. Thanks in advance.

There is probably some hidden layer inside (step 18 ). When you pull it out, at step 19, it is 3d, and step 20- 21 is basically performing a spread sink fold.

Yeah I see what you mean. I tried to sink it, and this is what I got. It doesn't look exactly like it does in the diagram. Sides A and B aren't radiating out at the right angle, and sides C and D moved slightly away from the center crease where they were previously on. But for a first try, is it along the lines of what it is supposed to be, or did I fold it completely wrong?