Printing postcards and dealing with the post office doesn't have to be scary. There are multiple sizes you can mail of printed postcards. Sizes vary from as small as 4.25"x6" to the most common large size is 6"x9". Other sizes are used and large sizes will go over 6"x9". Make sure that your thickness of paper is at least .009" or to say another way nine thousands of an inch thick. If you are using coated paper use at least 80# matte cover or 100# gloss cover. Some mailing companies have difficulty with gloss stock so check with who will be addressing and mailing. If you are doing the addressing at the same time as printing on a digital press(variable data printing) that is a non factor. If you are printing on uncoated paper 80# cover would be sufficient to meet .009" thickness.
If you want to print on gloss but your mailing company does not address on gloss you can use C1S(Coated one side)paper and they can address on the uncoated side.
On mailing you can choose First Class and Standard Mail. First Class mail will be quicker and more consistent delivery but will be more expensive. Locally it will be delivered in 1-3 business days and if you are mailing from one coast to the other budget 5 days. Standard Mail takes longer to deliver and is not as predictable on when it will deliver. When mailing nationally budget 10-14 days although locally it will be much shorter usually. Bottom line if you have time sensitive information first class will give you a better chance of success even with higher costs.
Postcards that are mass produced usually are funded by an indicia in the top right corner and sorted with zip code sequence and CASS certification. The funds are deposited in the account of the indicia holder and must be present at the time the mail is dropped. It is customary for the postage to be paid before the drop date. If you do not own an indicia most mailers and printers have one although if you are a non profit it would be worth having one in the long term to save on postage.
Written by Buzz Tatom
The Odee Company