From time to time Blenko must change the colors of glass we are melting in a specific furnace to a color that is not compatible with the color previously made in that furnace At the time of this writing we have 8 furnaces under fire thus 8 color opportunities.
The change of color within a single furnace mandates that we melt a batch of glass between the two colors to clean the residue color out. We usually melt crystal as that intermediate color and it dilutes the previous color and it's impact on the next color melt. Recall that our furnaces, once lit, burn 24 hours a day for years, or until they burn out.
This intermediate wash batch results in glass of a unique color that we cannot recreate again. The amount of the prior color left in the tank and the amount of crystal we add combines to make a distinct, new, on-time-only hue. As we are not measuring or quantifying any of these cleaning batches we can not recreate the identical color.
We usually try to make something fun and interesting out of these unique colors. Water bottles are a repeating favorite for One-of-a-Kind colors.