Crafting Expertise

You can craft nonmagical items you are proficient in the tools to craft in a quarter of the time, and magical items you are proficient in the tools to craft in half the time. Expertise in a tool further halves the crafting time.

(Example- if you have proficiency in smithing tools, you can craft nonmagical armor in 1/4 the time it takes and magical armor in 1/2 the time it takes. If you have expertise in smithing tools, you can craft nonmagical armor in 1/8 the time it takes, and magical armor in 1/4 the time it takes.)*

*see Xanathar's downtime activities for crafting times.