These 1.5ml tubes are designed to hold liquid samples during high-G spins.
They’re sturdy and seal VERY tight. I’ve used them for many years to store all kinds of paint (acrylic, lacquer, enamel).
Their volume of 1.5ml is IDEAL for small-batch mixing and the etched window allows you to document the contents with a Sharpie pen.
A cheap tube rack can be made by punching holes in a piece of foam or cardboard.
Foldable cardboard Tube racks are available here.
For those who wish to color-code there mixes, tubes of blue, yellow, and red are available.
Each bag comes with 20 individual tubes.