These high quality birthday invitations are printed on heavy weight matte card stock paper and come with mailing envelopes made out of superior paper. The invitations are post card style (non-folding) and come in a colorful design that your guests will absolutely love. There are 15 cards in total with 15 accompanying white envelopes all measuring 5×7 inches (A7 format). The kids birthday invitations for boys are single-sided and can be written on with pencil or pen without smearing. Not only do they come in vibrant colors but they are thick, making them more durable! Copyrighted design registered by Papery Pop.