a sticky book
Kids mess with an older guy asking if he wants to buy some weed from them. At some point he's tired of this and gives them money saying:
Keep your puff. Buy yourself a sticky book and a packet of sweets.
I can't find anything on "a sticky book" in Google except for books with sticky notes but I am not sure he means one of those. He obviously is talking about something for children but what is it?
This is from the movie The Gentlemen. It takes places in the UK so it is maybe something frome those parts.

Question

a sticky book
Kids mess with an older guy asking if he wants to buy some weed from them. At some point he's tired of this and gives them money saying:
Keep your puff. Buy yourself a sticky book and a packet of sweets.
I can't find anything on "a sticky book" in Google except for books with sticky notes but I am not sure he means one of those. He obviously is talking about something for children but what is it? 
This is from the movie The Gentlemen. It takes places in the UK so it is maybe something frome those parts.

Answer

a sticky book is an odd term, there be some specialist meaning but to me, a sticky book is one that you cannot put down.

Not being able to put a book down means that the story is so attractive you have to finish it at one go.

Answer

It means pornography: https://books.google.de/books?id=h0mcBQAAQBAJ&pg=PA743&lpg=PA743

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