Create Your Own Invitations & More Using these 5 1/2" x 8 1/2" Flat Cards you can create your very own Invitations or announcements for your wedding, anniversary, or other celebration. These are also great to use as Postcards, Announcements, Photo Cards, and much more. Our 5 1/2" x 8 1/2" Flat Cards are designed to work with your home inkjet or laser printer. Ultra Thick Stock Our Heavyweight 5 1/2" x 8 1/2" Single Cards are made from a 100lb cover (270 gsm) cardstock and are a 96 brightness rating. This means you are getting bright white, heavyweight, thick cards that feel & look more like the type of cards you would find made by the pros. Works on your inkjet or laser printer (and copiers too!). IMPORTANT NOTE: Please check your printer manual to make sure it is capable of printing on these cards before ordered. Printers must be able to handle 100lb Cover / 270 gsm cardstock Package Includes: 100 5 1/2" x 8 1/2" Ultra Thick 100lb Cover Blank White Cards