Postcards are an economical way to get information and offers directly to your customers. The standard sizes are 4 x 6, 5 x 7, and 8.5 x 5.5. It used to be that it was much more economical to print full color on one side and black and white on the other, but increasingly it’s only a small increase in cost to have color on both sides. We prefer the feeling of nice thick stock, but if the postage cost is a concern we can print on lighter stock.