There's an Onion article we rather liked a while back that neatly lampooned the shaver business, in which Gilette, frustrated by Wilkinson Sword's move to three-blade razors, promptly shouts: "F**k 'em - we're going to five blades."

A similar war - real this time - appears to be breaking out between HD DVD and Blu-ray Disc (BD) proponents. Desperate to get HD DVD's capacity up to something closer to its rival's, Toshiba last week unveiled a three-layer disc that can hold 45GB.

Now - with more than a little 'f**k you!' implied if not stated - TDK has announced a four-layer BD.

The beast holds up to 100GB of data. More to the point, it's recordable, and according to TDK, can support a write-speed double that of today's 50GB BD-Rs - or 6x (216Mbps), in other words.

The disc uses TDK's Durabis coating, announced last January, which finally allows BDs to be used without a protective cartridge, though they remain rather less resilient to scratches than DVDs.

Getting discs up to 100GB and beyond - 200GB appears to be the limit - was always part of the Blu-ray plan. TDK has talked about making 100GB BDs in the past. Alas, today's announcement, made in Japanese-language newspaper Nihon Keizai Shimbun, gives no indication as to when these discs might actually appear on the market. ®

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