Weighting isn't rarity.
The single thing people mix up most — watch how a part's frequency in the art is completely separate from how rare the finished token is.
Weighting ≠ Rarity
One shapes the art. The other is the collection's call. Here's the difference.
Weighting
How often a part appears in the artwork.
Rarity
How scarce the finished token is.
The short version
Weighting lives in the Generator. It only controls how often a part is chosen when artwork is assembled — a higher weight means a part shows up more frequently. In the animation, only 2 of 12 tokens rolled the gold hat, because the gold hat had a low weight.
Rarity lives in the collection. It's a separate policy about how scarce a finished token is — its tier (Common, Uncommon, Rare…). The collection assigns tiers; the artwork doesn't.
Because they're independent, a token with a common part can still be a rare token, and a token with a flashy, infrequent part can sit in the Common tier. Don't reach for weighting to make something rare — set the rarity. For the full picture, read the Rarity article.