Print your invitation wording on your printable cardstock. Play around with different designs since your ribbon will be in the middle of your sheet.
Tie your ribbon in a knot.
Making sure the knot is in the center of the front of your printed cardstock, tape the ends of the ribbon to the back of the cardstock (they will be hidden)
Use double stick tape or a mini hot glue gun to adhere your printed cardstock (with the ribbon around it) to your colored cardstock sheet.