A lot of specialise in only one or a couple of brands like Chanel, so you wouldn't use their products and services to authenticate a Givenchy For illustration. Quite a few precise authenticators will refuse to authenticate your bag by using photos only and ask for to contain the bag https://www.google.tl/url?sa=i&url=https://beroma.is/product/louis-vuitton-petit-sac-plat-2/