Most D&D 5e warlocks don't get armor proficiencies greater than light armor. This makes them easier to hit than most other classes. This is where Elven Chain comes in. It's a chain shirt with a +1 ...

The Elven Chain is a Rare set of Medium Armour found in Baldur’s Gate 3. The weight of the interwoven steel rings is offset by clever elven craftsmanship - rustling against your undershirt ...