For the final printing file, we usually need them to be vector file in PDF, PSD, Illustrator, or Coreldraw format. JPG and PNG sometimes are also OK, but the resolution must be higher than 400DP. And it will be better if you can prepare them as follows:

WITH OUTLINE:
Outline means to change the words to paths or curves.
Since sometimes we do not have the fonts you used and the word fonts may not match exactly in different computers, it may be missing or change when open at our side. Therefore, it is necessary for you to outline your press-ready files to ensure the fonts are exactly the same as what you want as well as to avoid the missing of your symbols and words.
WITH BLEED:
Bleed is the portion of the product that will be trimmed off when it is cut in to the final size.
Usually the bleed is 0.125″ (3mm) on all four sides. So when you are making your file, please build your print-ready design files by adding the appropriate bleed.
WITH CROP MARKS:
Please build your press-ready files by adding necessary crop marks, lines indicating where the paper should be cut to produce the correct size and shape.
WITH SAFE ZONE:
All the critical elements (text, images, logos, etc.) must be kept at least 0.125″ (3mm) inside the edge as anything left close to edge might be cut off during trimming.
