(nearly 1,000) were completed and sent to AlphaType for digitisation in the US in 1981–82, New Johnston finally became ready for Linotron photo-typesetting machine, and first appeared in London's Underground stations in 1983. It is the official typeface exclusively used by Transport for London and The Mayor of London ever since. The New Johnston Medium as the new standard is slightly heavier or bolder than the original Johnston Regular (or sometimes confusingly called Medium) and lighter than the original Bold, and has a larger x-height, made suitable for main text setting as well as large display sizes. The average x-height of the New Johnston is roughly 7% larger than the original as the limit for keeping the original Johnston flavour, which was fundamental. The larger x-height allowed larger counters, and type size (size of x-height in particular) and weight are reciprocal factors for legibility, but enlarging x-height can affect style and appearance. Since the original Johnston weights, Regular and Bold, were maintained as closely as possible, inevitably New Johnston Medium appears very close to Light and Bold. This is the whole point of this particular solution because New Johnston Medium works as the one-fits-all standard font for virtually every application from large type sizes for posters and signs to minute type sizes for pocket map maintaining much improved legibility. Punctuation marks are matched the diamond tittle, differing from Johnston's original design, enhancing the identity of London Transport. In 1990–1992 Banks and Miles, in partnership with Signus Limited digitised the first PostScript Type 1 fonts for the then London Transport under the auspices of the corporate design manager, Roger Hughes. Hughes and Jeremy Rewse-Davies, LT's design director, also commissioned New Johnston Book, a special weight with distinctive modifications to allow better representation on low-resolution laser printers. The New Johnston Book weight was designed specifically for high volume publications and its usage was intended to be restricted to sizes below 12pt. In 2002 the typeface was digitised on behalf of Transport for London by Agfa Monotype Corporation, with the addition of two further weights, Book and Book Bold, as well as corresponding italic variants. The revised font family – not commercially available – is known as 'New Johnston TfL'. In the early stages of digitisation, there was the chronic problem in letter-spacing, which seems to be solved more or less by now. A further change occurred in 2008 when Transport for London