We make plaques from 1.5mm 316 stainless steel and laser engrave them for tree plantings, building openings, and other public commemorations. This material is durable and suitable for outdoor use. You might choose this type of plaque for things like park benches, picnic tables, walls, and other outdoor structures. We can add one, or many, QR codes to meet your needs. We will send you a proof before production so you can test the QR codes work as you expect.