Salesman's cards would often have variations of the same button for buyers to choose from. These black glass buttons have differing tints.
Black glass with silver & blue luster.
Cattail design with interior twinkle rim.
I love having a large lot of buttons to pick through. This grouping had all kinds of buttons including pictures, storybook, twinkles, pressed pewter, Czech glass, waistcoat, black glass, plain brass, mother of pearl & velvet perfume buttons.
3rd picture from the top is a storybook button with a design known as the "Easter Boat Ride." It depicts 2 birds towing a 1/2 shell boat with 2 figures inside.
Several, like the navy twinkle buttons & those with a strawberry design have worked their way into bracelets, while others have been sold.