Metallic Resources’ electrolytically processed FOUR 9’s bar solder is higher in quality and purity by a factor of ten times compared to any other solder currently available. Independent testing has shown, and Metallic Resources guarantees, FOUR 9’s bar solder to create 25% less dross compared to the best “virgin grade” solders on the market. You’ll also experience a reduction in consumption for the same number of boards run. The special proprietary manufacturing process results in a bar solder that exhibits lower viscosity and surface tension in addition to greater fluidity. That drastically reduces bridging, icycling, cobwebbing, flagging, and solder voids while at the same time increasing wetting and wicking properties. So you get a very significant reduction in necessary re-work. All that together equals a very significant increase in profitability, not to mention better looking boards.