why in spanish people say impreso instead of imprimido?

because "imprimido" is simply not the right way to pronounce it (simply first grade grammar and semantic)

Impreso is the right pronunciation!!!

according to the Real Academia de La Lengua Española, both terms are correct, the usage depends on the usage of the word. for example:

El presente libro ha sido imprimido en los talleres de Mexico.

El presente libro ha sido impreso en papel reciclado.

Both ways are correct according to the rules past participle usage and verb conjugation.

It's simply a word that uses an irregular form.

A comparable situation in English would be "seen" instead of "seed", as in "I have seed many things in my life."

dont be tryin to mess with my mexican friends, wait let me ask u this... why do white people say "like" in every sentence .see it hurts doesnt it?!!!! dont make fun of diffrent races!OMG!!! ya retarded bithc!!!

WE ARE NO DUMB STUPID DUMBASS DON'T BE SO ****'N RUDE. WOULD YOU LIKE TO BE CALLED DUMB??? SO SHHHHHHH UP.