Investment-grade collectibles can provide owners with a host of financial and spiritual benefits – when done right.

That's the view of Lisa Best, research manager with Intelligent Partnership, a UK company that offers advice and training to financial advisors.

investment-grade collectibles such as this James Dean signed photo offer strong long-term investment potential

Speaking to FT Adviser this month, Best explained that devoting a small part of a well-diversified portfolio to collectibles offers good growth potential.

"'Investment grade' collectibles can provide diversification, inflation hedging, a physical store of wealth and an additional source of returns as well as the pure joy of ownership,” she said.

“Their value is driven by scarcity rather than mainstream market movements."

Best's emphasis on "investment-grade" collectibles or "the best of the best" is certainly a view we share at Paul Fraser Collectibles. It the rarest, most valuable pieces that have traditionally offered the greatest potential long-term returns.

Our PFC40 Autograph Index is a good example. It reveals that the scarcest, most coveted signatures have grown markedly since 2000.

James Dean signed photos in top condition (hugely rare) are today worth £18,000 ($23,000), up 16.3% a year on average from £1,600 in 2000.

Much coveted George Harrison signatures are up 20.3% per annum to £3,750.

Best added that "it’s vital to have a high level of expertise or a trustworthy specialist to avoid the pitfalls".

Paul Fraser has been authenticating and trading autographs and memorabilia for 40 years.

View Paul Fraser Collectibles' investment-grade memorabilia you can buy today.

Please sign up to our free newsletter to receive exciting news about autograph auctions.