The other kind of tridimensional printers...

[Externet]

I forget how are they named... optical something... Is there vendors that you know of, for 'benchtop' size?

They work by shining a laser onto some fluid that solidifies when hit by its ultraviolet light. Sort of a loca glue curing layer by layer to form a solid.

[fiveworlds]

Well it started with SLA (stereolithography) 3d printers. https://en.wikipedia.org/wiki/Stereolithography which was improved more recently to

CLIP (continuous liquid interface production) 3d printers https://en.wikipedia.org/wiki/Continuous_Liquid_Interface_Production

Using a process known as photo polymerization https://en.wikipedia.org/wiki/Polymerization

With a fluid liquid photopolymer resin https://en.wikipedia.org/wiki/Photopolymer

[Externet]

Thank you !. Now I can find them ! Good clues.