There are many options. Door signs and sliding signs come with peel-and-stick foam adhesive strip backing that can be used to apply the lightweight sign to any door. Or just buy labels which come with a removable liner and an adhesive back. Free-standing signs, sidewalk signs are also a great option. Open For Business signs made of plastic come with holes, attachment hook, and suction cups. You can also try our We Are Open Sign and Post Kit.