This question gets asked by some of our clients and the answer we give is that at MARKOTS, our Design Department calls the non-address side the FRONT, and the address side as the BACK of the postcard.
The question however is actually more than one of naming preference. By FRONT, the expectation is that the person receiving the postcard will read that side first and that in turn has implication on how the graphics and message is organized in the mail piece.
But when the mail piece arrives, we do not know for sure which side will be read first.
Bob McCarthy who is a direct response marketing guru advises, in an article on his blog, not to assume any one side is more important than the other. He has this guiding principle on the postcard layout:
“My approach to postcard writing and design is to put the same message on both sides. I know what you’re thinking: “that seems repetitive.” Yes, it is – because I know that many people will never see both sides of the postcard. Very few people ever read the whole thing.
You may want to design the two sides differently – you will need to because you have different space available. Each side might have a different secondary selling point or photo just for variety. But both sides must have your main selling point and, above all, a strong promotion of the offer.
Make sure everyone sees your offer – no matter which side shows up on top.”
So in short, give equal importance to both sides keeping in mind space constraints on the postcard especially on the address side.
And when our Graphics folks say it is the FRONT side, they mean the non-address side, and BACK is the address side. However, you should consider both sides equally important because as Bob says “you never know which side will be UP when it lands on the desk or kitchen table.”