Kids love stickers and, back in the Sixties, most kids loved comics too. Someone had the idea of combining the two and the result was a range of Sticker Fun Books published by both WDL (World Distributors Limited) and Century 21 Publishing.
I'm not sure exactly how many of these books were produced as I only had the four shown here. However the format appears to have been the same for all: large size, card covers, 8 interior pages. Stapled into the centre pages was a large sheet of full colour gummed stickers. The artwork on the stickers showed various segments from the stories within the books. For example some might show an arm and part of a torso, others showing part of an aircraft, another showing a face etc. The idea being that you'd stick the segments into their appropriate places in the story, adding colour to otherwise black and white strips.
There wasn't a sticker to cover every piece of black and white artwork, so for additional fun you were expected to colour the rest yourself. As you can see from the examples, I didn't really bother personally.
Basically then, these were colouring books that would do part of the job for you once you'd put the sticker segments in place. Although this passed the time pleasantly enough the results could be a bit rough if the stickers weren't quite placed properly, as shown in the scans here.
The Captain Scarlet and Joe 90 books each featured a story in comic strip format. Stylistically they looked just like the sort of strips that would turn up in the TV21 Annuals so were no doubt produced by the same team. Jim Watson provided the artwork, - a frequent contributor to the Century 21 comics and annuals.
In 1966, a couple of years prior to Century 21's Captain Scarlet and Joe 90 editions, WDL had produced Sticker Fun Books for Batman and Thunderbirds. Same format, but these only featured full page illustrations accompanied by short text to tell the story. In fact the Thunderbirds one didn't even have a story, just a series of eight illustrations introducing the basic premise.
Although simplistic by modern standards the Sticker Fun Books were an enjoyable enough piece of Sixties nostalgia. Priced at 2/6d each (12 and a half pence) they were over four times the price of the average comic, but they'd be given as Christmas stocking fillers or perhaps as an extra birthday present.