Banners and shields made with uncommon and rare banner patterns still have common rarity.

Steps to reproduce:

1. Obtain a banner, a dye and a Thing Banner Pattern
2. Use them in a loom to get a banner with the Thing pattern applied. Note the banner's rarity
3. Obtain a shield
4. Apply the banner to the shield. Note the shield's rarity

Observed result:
Both the banner and the shield with the banner applied have the Common rarity.

Expected result:
Both the banner and the shield with the banner applied have the Rare rarity.