How do you date a post card?
It is important to remember when dating post cards, the date is when the card was made, not when the card is used. If a card has been mailed the post mark helps. Zip codes were put into use in 1963 so any card that has a zip code was made after that date. Collectors often record on the card back itself the date and place of purchase. You know the card is older than that date. Sometimes the subject itself helps. Look at hairstyles, clothing styles, automobiles and even street scenes can be used for dating. Just like many collectibles, post cards are broken down into time periods or eras.