Here is a step by step guide to making the invite with suggested dimensions:
a) Select a doily that can fully cover your old cardstock when folded on 4 sides. I used found cardstock, which is really just an old library card measuring 4 and 7/8" by 3" (124 by 77mm) and a doily 7" (178mm) in diameter. I love it that old paper stock usually comes in round imperial measurements.
b) Fold in the flaps by the sides first, followed by the flap below.
c) Fold down the top flap and seal it with a kiss. In this case, I used Herma Self-adhesive label No. 2213, 8mm in diameter.
d) Turn card over and addess with another adhesive label. I typed guest names on Herma adhesive label No. 2253, 19mm in diameter. I could use a round label as guests to this party did not have long names.
Play around with sizes and textures. Cardstock with colour works better than white ones as the contrast enhances the pattern of the doily.