Arknights Wiki

The Polyester Pack is an upgrade material in Arknights.


A pack of polyester used in industrial production. Can be used for a variety of upgrades and for production in the Factory.

After a series of processes, it meets the standards and general needs of most products on the market. It can also be used to process some special materials.


The third of Ester-type upgrade materials, these polymers derived from Polyester comes in greater quantities and have many uses, which includes Operator advanced skill upgrades and Mastery training, and the Elite 2 promotion of 4★ and 5★ Operators.



Regular drops

Operation Sanity Drop rate Sanity per drop
12 Sanity icon.png Rare (~36%) ~33 Sanity icon.png
18 Sanity icon.png Rare (~39%) ~46 Sanity icon.png
18 Sanity icon.png Uncommon (~48%) ~37 Sanity icon.png
18 Sanity icon.png Rare (~38%) ~47 Sanity icon.png
18 Sanity icon.png Uncommon (~55%) ~33 Sanity icon.png
18 Sanity icon.png Rare
18 Sanity icon.png Uncommon
15 Sanity icon.png Rare
18 Sanity icon.png Common
15 Sanity icon.png Rare
18 Sanity icon.png Common
18 Sanity icon.png Uncommon

As seen on the table above, the best operation to farm Polyester Packs is 7-4 if one only needs them, or 3-8 if one needs them to process Polyester Lump.png Polyester Lump due to it being a special drop there.

Extra drops


Product Material(s) LMD Morale Requires
Polyester Pack.png
200 LMD icon.png Morale icon.png Level 2 Workshop

See also