I’ve had a number of mugs printed by Zazzle, and most of them came out gorgeous; but last summer I was peeved enough by a delivery cock-up to want to take my business elsewhere. Recently I got around to doing something about it, with even more disappointing results.

Threadless would not let me sign up. I can’t tell which of my address, handle and password offends it, let alone how.

Cafepress failed to upload my design.

Spreadshirt and CustomInk cannot do a wraparound design on a mug.

Who else is out there? Maybe I have cooled off enough to go back to Zazzle.

You probably haven’t noticed the absence of a link in the upper left, “buy 2D printed objects”, which went to my catalogue on Zazzle: shirts, mugs, posters. ( . . more . . )

I got a notice from Zazzle that if I don’t post at least one new product in every fifteen months they’re going to charge me a Non-Contributing Account Fee. So here’s one. I can spin more variations on this theme until the cows come home.

Sometimes I search my blog for this picture and scratch my head in puzzlement that it’s not here, before remembering that I posted it on Google Plus back when I used that.

So here it is. Stephen Guerin (the shaven one) displays his canvas print of one of my designs.

The colors came out better than I hoped, in stark contrast to a couple of mugs with related designs that I got from the same shop.

I’ve had other designs made in steel but not this one. (The sintering leaves the steel highly porous, so liquid bronze is brought in by capillary action to fill it; the result is about three parts steel to two parts bronze – if I understand right. Hence the color.) (Later: I was mistaken: the steel powder is not sintered but glued; I guess the bronze burns away the glue.)

While it was on its way to me, I thought of some improvements. ( . . more . . )

I’ve been designing printable models of the Lawson-Klein surface

To minimize the distortion of the projection, I want the projection center to be as far as possible from the surface. One thing I tried was pursuit: starting with an arbitrary point P in S3 and an arbitrary point L(u,v) in the surface, move (u,v) to bring L closer to P while simultaneously moving P away from L. This gets me nowhere so far: either it fails to converge or P converges to the antipodes of L, which is also in the surface (change u by π).

My newest design on Shapeways is a model of the Lawson-Klein surface : a stereographic projection of

( cos(u)cos(2v), cos(u)sin(2v), sin(u)cos(v), sin(u)sin(v) )