Desygner.com is free and really easy to use. Just create your invitation and send the file to a printing company.
Edit: An alternative site is Canva.com . It's free as well, but not as practical in my opinion.
https://desygner.com/design/?id=50IgnO1FiJZ
Loaf, crumb and recipe all in one image file creator. Free to use, modify or ignore.
By the way those aren't stock images. I just made them and they are freaking delicious