Blood Type A, B, or O it does matter, you want blood!. What matters is advertising your event so that the maximum number of people see it and plan to donate blood. And what better way than to place yard signs on the heavily trafficked corners in your neighborhood. And Sign.Builders is ready to produce as many signs as you think you will need. Just select the size and material you want your Donate Blood sign(s) printed on and place your order. Your custom signage will be on its way to you within 48 hours or sooner if you select rush service.