Okay, I did some research.
Without investing in some expensive machinery, these can't be really made seamless. A smooth is possible, but not a ribbed one
I'd have to make it flat, and then glue together. There is some special latex glue, which fuses the ends together. I hope this is acceptable.
Now, I'd like to know the opinions from you, guys.
-) What do you think about the shape? it it cylindrical, tapeered or hour glass shaped? I guess tapered, as Eric (Darth Aloha) says that you cut the ribs to fit your size.
-) Who many ribs do you see?
-) are the ribs round or half round? I think half round. What do you think the diameter is?
Thanks!