The cool thing about these invitations is that it really was not that hard to do! I actually used BOTH my Cricut and my Silhouette Cameo to make these. The outside is made from the Batman cartridge and the inside is designed on the Silhouette software. You could also use Word to do it since it's just a simple square but for me, it's easier to do it on Silhouette only because I can get it to print and cut exactly where I want :)
I downloaded the Batman Forever font from dafont.com :) Free!
Have a happy weekend!