These high quality birthday party invitations are printed on heavyweight matte card stock paper and have mailing envelopes made out of superior paper. The invitations are post card style (non-folding) and come in an colorful design that your guests will absolutely love. There are 15 cards in total with 15 accompanying envelopes all measuring 5×7 inches. The invitations are single-sided and have a varnish coating on them so they can be written on in either pencil or pen without smearing. Not only do they come in rich vibrant colors but they are thick, making them more durable!