Engineer's Blue is a lubricating paste that marks metal surfaces in a clear, bright blue color. It spreads evenly and stays wet for months without drying, so it can be left on machine surfaces continuously. This allows it to locate high spots and improper fittings on bearings, gears, and other precision parts, aiding quality inspection and precision machining. It is available in 38gm tins for Rs. 550 each plus applicable taxes, and can be shipped across India.