Cheaper paper and printing lead to a rise in paper packaging, particularly in the food retail trade. One of the cheapest form of advertising was paper bags and wrapping printed with the grocers name.

By the mid 1870's, William also owned several warehouses in Leeds and was already employing six travelling salesman, one of whom was William Mart. On 31 January 1877 William Roberts died, his eldest son, John, was not yet sixteen. William Mart acted as a principal manager of the firm.

In 1882, John Roberts came of age and joined the partnership, which became known as Roberts, Son & Mart.

The business was flourishing in 1888 the partners opened a warehouse in Birmingham. In the same year the firm, now described as paper merchants, lithographers, printers and paper bag manufacturers, changed its name to Roberts, Mart & Co and in 1890 the partners took the decision to convert into a limited company.