A supply that you will find to be most necessary is a heavy cardstock of thickness, color, and design, of your desired choice. I think most common color is an off white color. You can buy bulk cardstock or you can find special paper that has already printed patterns on it. Paper also has different textures so this is important to make note of when choosing papers.
After you have chosen appropriate paper for your invitations you can decide if you want to completely print your invitations or if you want to hand write them. All you will need for handwritten invitations is some nice markers. You can choose whatever colors you like, and there are even gold, silver, and copper colored markers that will work well. If you decide to print the invitation you can find basic templates for envelopes and invitations on Microsoft word. There are also many different fonts that you can use right in the program. You can also choose to incorporate a picture you and your fiance which can be copied and pasted into the card. Some more ideas to suit a summer wedding are pictures of a sunset at a beach or brightly colorful summer flowers. Many nice sayings and wedding invitation formats can be found on the internet as well.
Other supplies that can be used for your wedding invitations are ribbon, faux flowers, sequins and pearls. All of these items can be used as embellishments for your decorations. Another fun way to embellish your wedding cards is using paper cut outs. You can cut out various shapes of flowers from different colored paper to suit the theme of a summer wedding, and you can layer them on top of each other. Adding pearls or pretty beads also make these cards pretty and special. A simple bow can be made from ribbon and it can be glued to the card to make it tool like a present.
All of these ideas can help you make your own personal summer wedding invitations. Make sure no matter which methods you decide to employ that you love the finish product, and remember to enjoy the process because this is something you will remember forever!