Muppet greeting cards (Hallmark)

JC Hall began creating greeting cards in 1910 for the Hallmark company. Over the years, more and more licensed characters began appearing on their cards, from Mickey Mouse to the Peanuts gang. The Muppets began appearing in the mid 1970s, and continued to do so sporadically over the years.

Birthday Cards
Miss Piggy appears on the cover of this 1981 Birthday Card Cover:"I wanted you to have something exciting and marvelous for your Birthday..." Inside:"But I couldn't get away...Anyway, Happy Birthday"

Valentine's Day
Gonzo appears on the cover of this 1981 Valentine's Day Card Cover:"Oh this blazing, burning, churning sensation deep within my heart! It must be the passionate fires of love!" Inside:"It's either that or the pizza I had for dinner."