Hi, I have two Beatles autographs in my collection. One of them is dedicated to me personally (obviously my favourite), whereas the other has just the autographs of band members. Now I have started to view my collection as an investment, I was wondering which has the most potential? - J Fuller, London

Having worked in the autograph business for many years, I've learnt that this one really comes down to a matter of preference and can balance on a number of factors.

As I'm sure you have realised, many autograph collectors would prefer not to have dedicated items in their collection as it disrupts its continuity. There is also the fact that not many people would want to see "To Gary" among their autographs when their name is, for example, Brian.

However, there are a few exceptions to the rule.

Some famous figures rarely sign any items of memorabilia, making it very hard to gain any form of autograph at auction. In this case, the fact that the item is dedicated to a particular person is waived for the sheer rarity of the piece.

For example, we currently have in stock an album sleeve of the Beatles' A Hard Day's Night, which is signed by all four members. Ours doesn't include a dedication, but as one of only 8-10 known to exist, I'm sure a serious collector would not let that hamper his decision to buy.  

In extreme circumstances, the addition of extra text in the signer's hand can actually heighten the value of the piece. Many collectors will pay more for those important few lines, specifically if the message is charming or has close relation to their chosen area of interest.

Our James Dean signed photograph reads: "to Hana - my very best from (the thinker) James Dean". This short reference to his position in the photograph and Rodin's famous sculpture provides us with a brief glimpse of Dean's good humour and has heightened its value far beyond that of our yearbook page, where the Rebel Without a Cause has simply signed below his entry.

Likewise with our Charlie Chaplin signed photograph. Simply inscribed: "To my friend Frank, from Charlie Chaplin", the piece is dedicated to Frank Traughber, who worked as Chaplin's office boy for just a year from 1919 to 1920.

With Traughber claiming that he signed more than 100 autographs a day on behalf of Chaplin, we can guarantee that this one, at least, is genuine. This fact, combined with a stunning shot of Chaplin in his most iconic role, places its value higher than other signed photographs, which generally sell for around £3,950 according to the PFC40 Autograph Index.

However, as you say, the dedicated Beatles autograph in your collection is your personal favourite, so I would suggest holding on to this for its sentimental value rather than investment potential. Instead, you should consider the worth of the other item, that you are clearly less attached to and is likely to be far more popular at auction. The aforementioned PFC40 Autograph Index should certainly help with that.