Products made by blind persons and sold or distributed in this state as blind made may bear a label affixed directly to the product reading "MADE BY THE BLIND" and shall show the distributor's or manufacturer's name. Any product bearing such label shall have been made by blind people to the extent of at least seventy-five percent of the labor hours required for its manufacture. No other label, trade name or sales device tending to create the impression that a product is made by blind persons shall be used in connection with the sale or distribution of such product unless the product shall have been made by blind people to the extent of at least seventy-five percent of the labor hours required for its manufacture.