The Origami Forum

In origamania, page 78, step 18
http://design.origami.free.fr/albertino ... amania.pdf

What is exactly the "black square" ? It does not seems to be the "hole" at the bottom of the base, but it seems to be just a part of the paper...
And what is the 3D-arrow ? the point of view for the next step ?
I am quite confused !

[img]http://img409.imageshack.us/img409/3161/st184gh.png[/img]

Maybe I should fold this befor I post but....

the 3D arrow is just the point of view for the next step (you were correct).

As to the black square, I think it is a in-out sink, so the square will come up. If you look closely at the black square, you see vally fold lines, so follow those.

ok i passed it, time to sleep now

In fact there are 2 symetric sinks, on the left, and on the right of the face showed step 17.
The draw of the step 18 seems to be full of errors, if somebody is confused, use the pictures of the steps 19 and 20...

And the funny thing is the fact that you have to unfold everything to sink during the step 22