carbon paper
US /ˈkɑːr.bən ˌpeɪ.pər/
UK /ˈkɑːr.bən ˌpeɪ.pər/

1.
papier węglowy, kalka
a thin paper coated with a waxy pigment, used for making a copy of a document as it is being written or typed
:
•
She used carbon paper to make a duplicate of the invoice.
Użyła papieru węglowego do wykonania duplikatu faktury.
•
Old typewriters often required carbon paper for copies.
Stare maszyny do pisania często wymagały papieru węglowego do kopii.