Symbol Test Tubes Metal Sign

About the Test Tubes design

Both tubes stand as plain squared-off rectangles with no rounded bottom anywhere, their tops widened into caps whose corners are the only curves in the drawing. Each cap holds a long horizontal slot, and below it the tube narrows to a shorter square opening that stops well above the rack. That rack runs the full width as a deep box, tall enough to swallow nearly half the height and leave only the upper thirds of the tubes in the open.