With the magnetic powder in hand, the next question was,how to coat it onto the tape. At first, Ibuka and his staff tried conventional methods, coating the tape with a spray gun. They also dissolved the powder in transparent lacquer and sprayed the liquid with a spray gun. The finished tape would barely reproduce audible sound. In addition, more material would be sprayed away from, rather than onto, the paper and thus produced an uneven surface.
This spray-gun coating technique was tried at the newly-established Yama-no-ue factory. Still empty, spacious, and with a brand new floor, it proved to be just right for making the new tape. One day Kihara, so absorbed in his work and eager to proceed, laid the paper on the floor and started to spray the liquid powder onto it. Naturally the brand new floor was blackened by the spraying and Kihara was severely scolded by Akira Higuchi.
Ibuka learned somewhere that a hairbrush made of badger's hair would be ideal for coating. Kihara bought one in Ueno for 800yen, which was a considerable sum for Totsuko. He stretched the paper tape on the floor and, like a machine, brushed on the magnetic powder coating. But this made little difference from the spray-gun method.
Kihara changed the tape width, as he thought 8mm was too wide. He changed it to 6mm -- actually a quarter of an inch, but nobody realized it at that time. How could one reduce the width by 2mm without the slightest fluctuation in width or notches? Place two razor blades exactly 6mm apart from each other and pull the paper tape along and through the blades. That was the manual tape cutting machine.
After further experimentation, Kihara realized that the finer the magnetic powder, the better the tape performance would be. However, no one knew how to make such fine powder. At that time a company called Papilio Cosmetics frequently ran newspaper ads for face powder, with a microphotograph which compared the finesse of its product with those of its competitors. " That's it! " thought Kihara.
Believing that Totsuko could obtain the know-how to make fine powder from this cosmetics company, Morita went to see the president of Papilio Cosmetics immediately, even though he had never met him before.
" Our company is now developing a sound recording machine, " Morita briefly explained. " Since we are not in the cosmetics business, could you kindly instruct us on how to produce fine powder? " " How fine will your powder have to be? " Papilio's president asked. " Well, it must be 3,000 to 4,000 mesh, " Morita replied. Upon hearing this the president laughed, saying, " That's a totally different level, Mr. Morita than what we produce. If a woman applied 'oshiroi' of that fineness it would be too light to stay on her face. It would just fly off like dust, you know! "
Totsuko continued the process of trial and error, but prpblems kept arising where Ibuka and Morita least expected them.