Coley Porter Bell's new logo for the Museum of London (right). Pentagram's former logo for the institution is shown on the left

London has more than its fair share of great museums but the one that bears the city's name has always been a bit of a disappointment – the ugly stepchild to the splendors of the V&A, British Museum and others. However, a £20.5 million refit for the Museum of London is planned for 2010, heralded by the release of this new logo...

While the South Kensington museums glory in Victorian magnificence and the British Museum's neo-classic bulk dominates Bloomsbury, the Museum of London's main site is a permanently wind-blown concrete bunker tucked away between St Paul's and The Barbican. Welcoming it is not. Inside the galleries feel cramped and uninspiring with none of the interactive fun for kids of, say, the Science Museum. Hopefully the impending refit led by architect Wilkinson Eyre will address those issues but the Museum also has the problem of being spread over three sites – the main London Wall building, plus the Museum of London Docklands and Museum of London Archaeology in Islington.

Coley Porter Bell's new logo attempts to link the three sites. According to the Museum press release "The colour palettes of Museum of London Docklands and Museum of London Archaeology’s new logos, feed into the layers of the main brand mark, creating a family of three destinations, united in a single mission: to inspire a passion for London. And London is written through the new logo, whose typeface echoes the city’s iconic street signage."

We're not sure about where the "passion for London" comes through but the central idea of mapping the changing size and shape of London through its history to create the coloured layers seems an intelligent and appropriate direction to take.

As the press release has it "Coloured layers map the shape of London over time, reflecting the ever-changing, diverse and dynamic make up of London and Londoners, past, present and future."

Such overlayed logos are, of course, nothing new. Respondents to Brand New's coverage of the redesign have already pointed out the similarities with this

And this

Bill Gardner at Logolounge picked up on the trend as early as 2003: "Let's face it: The old rule that dictated that any really well-designed logo had to A) be reproducible in only one color, and B) that color had to be solid, not screened is gone. Sure, there are still challenges to be faced in playing fast and oo9se with these rules when a job must actually go on press, but the internet is much more forgiving.

"There are many logos today that have transparent qualities that reveal themselves through multiple layers. These designs can be very compelling especially since they are still novel enough to stand out from the already crowded world of flat one, two- and three-color logos."

From Logolounge's 2003 trend report: 1.Design Firm: mires Client: Fusion Media 2.Design Firm: Cato Purnell Partners Client: Neil Henson Fashion Bytes 3.Design Firm: Landor Associates Client: Altria

As he noted in further coverage of the Overlay trend in 2006, "One of the driving factors behind the transparency trend is pure technology. Adobe Illustrator has made the additive color process a click away through layers with or without gradation. That means the effects can be controlled in a vector environment which is more conducive to experimentation than Photoshop."

Nevertheless, when there is so much gratuitous swirlyness, shininess and marbelisation going on in logo design, it's refreshing to see a trend applied with a rationale that actually stands up to (a little) scrutiny. And it gives hope that the Museum itself will be a lot more exciting to visit in future: which is pretty important to those of us who have 8 year-olds currently 'doing' the Tudors and for whom a project deadline looms...