Linotype machine
"Klempen" is a constructed word from the German "plenken" (meaning "to add inappropriate spaces", itself a borrowing from the English "blank") and "klemmen" ("to wedge", possibly a reference to Linotype machine operators' slang term "wedges" for the spacebands used to implement justified spacing), exchanging the "k" and "p" in such a way as to suggest both phonetically and orthographically its relationship and opposite meaning.