what keyboard you using? I recommend you get a set from Kai
his key is awesome!
http://forum.lowyat.net/index.php?act=ST&f...0#entry51313986

check it out.

Only PBT is possible to print Dye-sub custom image on,
black PBT key are impossible to make custom image on...
Because the printing color has to be darker than the keys.

it's a technical problem.

it depend on what logo/image you want,

ABS has different technique to print,
the most common one is pad print, will fade very fast.

laser can do on PBT or ABS, they will burn groove on the key,
but after, hole burn can fill with color, will last longer,
if no filling or filling not even, the key will feel not flat.
then is Double Shot, can be done with ABS or PBT, at the moment only ABS commercially available,
made of 2 different mold, so will become 2 color for one key, too detail design cannot be comply.
and sometime when used, the key will wear down uneven, then you can feel some part of the key is not even.

Dye-sub, only can be done on PBT keys, and can only print darker color on lighter color key.
eg.. black on gray, gray on white, but can print as detail as photos on a key.
this key will feel most flat, won't have any uneven feeling on the surface.

depend on what your design to do on a key, you can choose method and materials.

So you give up trying to get keycaps after seeing a so complicated article?