A Greek newspaper accidently printed its first issue inside out and they continued the tradition for over 100 years!

Estia is a newspaper published daily in Athens, Greece and named after the goddess Hestia. It is the only daily newspaper written in katharevousa, a purist and archaic form of modern Greek. Katharevousa was abolished as the official administrative language in Greece in 1976. 

Estia is aligned with the conservative, right-wing politics and the use of katharevousa is generally associated with conservative politics in Greece. Estia was first published in 1876 by Adonis Kyrou I and it was originally a weekly publication as a literary magazine. 

The paper’s first publication was accidentally misprinted with Page 1 being on the back and Page 2 on the front. Kyrou decided to continue printing the paper in this way and the tradition continued until 1997. 

Why until 1997? That's when they switched to a computerized system, and there were complications in getting the computer to get the page flip right, so they abandoned it. 

(Source)