The term black label is used for assets that are considered worth purchasing as long term investments and require the buyer to spend more money to purchase the asset. The cost of a black label asset will be higher than start investment assets.
Because GWJ is using fashion as inspiration for our financial terms, black label investments do not go out of fashion. The products are timeless and higher end.
A black label blue chip stock would include Travelers Companies and American Express. There is no official list of blue chip stocks but according to Motley Fool, there are 30 companies in the DOW Jones that meet the standard to be a Blue Chip. Most of those companies do not get the black label because their product lines are focused on utilitarian mass production for the masses.
A black label stock outside of the blue chip category, would be companies such as BMW, Diageo PLC, Estee Lauder & Roche Holding AG.