Woolco was a German low-priced brand on first 17 cm (red label) and later on 20 cm (blue label), 1929 - 1935.
The records were only sold in the Woolworth department stores.
The recordings were made by Kristall, there are often found artists on Woolco records, who were under contract at Kristall.
But there also got matrices of the English parent company Crystalate Company.
German crystal recordings is employed a "J" before the matric number, English matrices a "C".
Recordings were also released under WUBA and Mercury & Frani.