Britney Spears' Book is Done, Delayed Because of Paper Shortage

Britney Spears' tell-all is finally completed, sources with direct knowledge tell TMZ, but we've learned there's a delay in releasing it and it all has to do with .... THE SUPPLY SHORTAGE!

Sources close to Britney tell us ... she recently wrapped up the dishy memoir, which is set to be published by Simon & Schuster. We're told Britney and co. are aiming for a release date in January -- but there's a paper shortage that has upended the plan.

What's more ... our sources say there's no clear date on when the shortage will be resolved ... hence, there's not a firm release date.

A report from Publishers Weekly earlier this year pointed to a couple of major factors for the shortage -- more people started ordering books during the pandemic, decreasing paper supply. There's more -- people walked off their manufacturing jobs at paper plants, causing an ongoing labor shortage.

As we reported ... Britney's tell-all deal she signed back in February scored her a $15 million advance. The deal was one of the biggest for a memoir, behind the Obamas -- who signed with Penguin Random House for over $60M.

Of course, Britney's book will have plenty of material -- from her days as a child star, to finding superstardom and the falling out with her family during her conservatorship.