Once in Argentina, the Biros found several investors willing to finance their invention, and in 1943 they had set up a manufacturing plant. Unfortunately, the pens were a spectacular failure. The Biro pen, like the designs that had preceded it, depended on gravity for the ink to flow to the roller ball. This meant that the pens worked only when they were held more or less straight up, and even then the ink flow was sometimes too heavy, leaving smudgy globs on the paper. The Biro brothers returned to their laboratory and devised a new design, which relied on "capillsry action" rather than gravity to feed the ink. The rough "ball" at the end of the pen acted like a metal sponge, and with this improvement ink could flow more smoothly to the ball, and the pen could be held at a slant rather than straight up. One year later, the Biros were selling their new, improved ballpoint pen throughout Argentina. But it still was not a smashing success, and the men ran out of money.