Those of us who grew up on comics in the 1960s and 70s may remember when The Dandy and The Beano occasionally featured 4 page pull-out flyers in the centre pages. These lively ads would promote new DC Thomson comics or, more often than not, free gifts in existing titles. (Back in the days when free gifts were a rare treat in comics.)
These four page flyers, printed in navy blue ink on pink paper, were exciting because a) news of a new comic is always exciting, and b) even if it advertised an existing comic, free gifts were accompanied by new stories joining the comic.
Here's the flyer promoting "the new big Dandy" which was in The Beano No.1494, March 6th 1971. The cause for celebration was The Dandy and The Beano both increasing their page count from 16 to 20. Laughable as it seems now, those few extra pages were a big deal back then. They also compensated for the price rise from 4d to 2p (5d) a few weeks earlier when Britain went decimal.
These flyers are very collectible today. This is the actual comic and flyer I had back then, and the edges are a bit tatty now but I've tidied it up in the scan. The main images of Korky and the free gifts are by Charlie Grigg, but the strip of kids reacting at the top of page one looks like the work of Vic Neill. (The centre pages of the flyer artwork is a mixture of clippings from the strips and staff art.)
These 'pink inserts' were a great way for DC Thomson to promote their comics. IPC imitated the idea from the late 1960s, but the Thomson flyers always looked better designed to me.