A client visited our showroom yesterday and interested in a memorial plaque for her uncle, with words and photo being engraved on granite plaque.
She once had a plaque with photo being painted on it (I do not know how the photo was painted), but the photo disappeared gradually as it is not weather proof. For people memorial plaque, I suggest that photo being engraved by laser or by hand is the better solution, no colour added, it can last quite a long time. The advantage of laser engraving is, the photo being engraved can be very fine, the disadvantage is, it is shallow. The people memorial we offer is handmade engraving, it is not as fine as laser engraving, but it is a handicraft indeed.