Thank goodness I read your article yesterday, it saved me a potential nightmare. I only had 44 cent stamps on my save-the-date envelopes, but a very helpful woman at the post office showed me the measurement specifications and told me I needed to add 20 cents to each envelope!
Crisis averted, so thank you a million times over!

Nice article! At Perfect Postage, we love custom postage! Just working now on some monogram stamps for an April wedding.