Removing White Boarders (Bleed)

You need to do the right file set up and print on 'oversized A3' paper in order to get rid of white boarders.

file
new
bleed-3mm-ok

OR

open artwork pdf
file-document setup
bleed-3mm-ok

when printing double sided add a safety
open rulers
take rulers from corner and drag to black corner
repeat and rest another ruler at 5mm
add allaround page and save as pdf

NOTE BEFORE clicking ok and SAVING as pdf
marks and bleed
select the marks you want (trim marks, registrations marks, colour bar)
select use the document bleed setting-save pdf