Green’s Dictionary of Slang

borax n.1

[SE borax, cheap and shoddy material, esp. as peddled by immigrant Jews; supposedly orig. in the practice of a maker of borax (acid borate of sodium) soap offering coupons for cheap furniture]
(US)

shoddy, cheap manufactured goods; also attrib.

Show quotations
[US]Mencken Amer. Lang. (4th edn) 218: The instalment furniture stores have also borrowed from the yiddish. They are called by their salesmen borax-houses, and the borax apparently comes from the Yiddish borg, meaning credit.
[US]R. Chandler High Window (1951) 159: A smoking stand from a cut-rate drug-store, a standing lamp from the basement of some borax emporium.
[UK]Partridge DSUE (5th–8th edn).
H.J. Rosenberg Dict. Business 53: Borax. Inexpensive items (e.g. furniture) that are usually poorly designed and constructed [HDAS].
[US] ‘Miscellany’ in AS LX:3 283: Borax was usually applied in a derogatory sense to cheap furniture as well as other merchandise sold in a discount store or on an installment plan.