Do you think that Archie will have his image on a royal stamp?
Only if all of Williams' line dies and Archie becomes the heir apparent to the throne.
Minor royals - and Archie isn't even royal yet - don't get onto stamps in the UK.
He really is irrelevant to the future of the monarchy - a much loved child I am sure but in the big scheme of things a footnote in history - a name that will appear on family trees but with no real stories told about him unless he creates some scandal or other.