The StainTray has a black base made of tough ABS plastic that can withstand a wide range of chemicals (avoid chlorinated hydrocarbons). It will accept up to 20 slides on four plastic rails covered with a polymer strip to hold slides perfectly even if tray is held at an angle. When humidity is needed, wells between rails will hold up to one mL of water securely without splashing. Middle wells will hold up to 2 mL each. Rails are raised not only to avoid water touching the slides but to make them more easily retrievable. The base will also hold excess stain solution dripping from the slides. Four rubber feet ensure greater base stability. Units are stackable for space-saving purposes.