The Brothers' War Collector Sample Booster has variants:
Explore this pack in Sealed.

Sheets

Sheet nonfoil_rare_mythic

At rate 1/136 (0.74%)
At rate 1/272 (0.37%)

Sheet foil_uncommon_retro_artifact

At rate 5/108 (4.63%)
At rate 1/108 (0.93%)

Sheet foil_rare_mythic

At rate 1/120 (0.83%)
At rate 1/240 (0.42%)