MaryJane and Phil O'Reilly were making denim in London as a way to earn some money when MJ was there on a dance scholarship with the Royal Ballet from 1970. On the way back to New Zealand they spent some time in Tucson, Arizona and while there they were also able to use these making skills to earn their keep. When they arrived back in New Zealand in 1974, the Cook Street Market offered an opportunity to continue with their successful business. Under the label Black Sheep. MJ did all the sewing and Phil, a graphic designer, did the design work and made and applied all the hardware to the denim. Judith Baragwanath wrote in the Sunday News that they had "down-to-earth style with lots of guts, dark heavy 14 oz denim, solid and clever stitching and the cut supreme". MJ and Phil would sew all week and then go to the market on Fridays and Saturdays, often selling out of stock and going home early. They had some quirky branding such as the leather label stamped by Phil himself. The denim jeans, skirts, dungarees, vests and bags all came with a Certificate of Title and they also screen printed t-shirts with the certificate. In an editorial piece at the time it was claimed that "The denim used in Black Sheep is the heaviest available therefore the style and durability of the garments has put something back into the jeans market which has sadly been lost in a fast moving throw away society". Read more about 1970s fashion in the New Zealand Fashion Museum publication The Age of Aquarius: A 70s Revolution in Fashion.