The difference between a $40 reproduction and a $4,000 original comes down to what you know before you buy. Here is how to authenticate a piece, grade its condition, and place it in time.
Reproductions and outright fakes flood the market. Porcelain enamel has a physical signature that modern reprints struggle to fake — learn to read it before money changes hands.
Condition moves prices more than almost anything else. Collectors describe signs on a rough 1–10 grade; here is what each band means and roughly how it affects value.
Full gloss, crisp graphics, no meaningful chips or fade. Rare and priced at a steep premium.
Bright color with only minor edge chips or a few field nicks. The sweet spot for most serious buyers.
Honest display piece with visible chips, light fade, or small touch-outs. Strong value for its look.
Heavier loss, rust bloom, or fading. Bought for rarity, "man-cave patina," or as an affordable example.
Major porcelain loss or structural rust. Value only in the scarcest pieces or as decor.
Logos, manufacturing marks, and materials all shifted across the decades. These clues help you date a sign or globe within a decade or two.
Heavy multi-piece porcelain signs and rare one-piece "baked" glass globes. Ornate, serif-heavy typography and elaborate crests.
Glass lenses set into metal or Gill glass bodies. Bold die-cut shapes and streamlined Art Deco lettering arrive.
Big, colorful porcelain and the first painted-metal and lit plastic signs. Date stamps and maker's marks appear on edges.
Injection-molded plastic globes and internally lit box signs replace porcelain. The classic petroliana era winds down.
Two signs from the same brand can differ tenfold. These are the levers that move value, in rough order of impact.