I bought them for my 3 mth old child and he liked them from the start. at the beginning it was just me taking his hand and stroking different fabrics. at that time especially colours book was useful as each page was in a different colour. now he is 6mths and he reaches for them himself and tries to stroke images as we both turn pages. they are a good size too (about half of A4 page) and sturdy, "dribble-resistant".
Absolutely stunning childrens books, clear pictures, lovely textures to feel, and simple words to learn. Cannot recommend highly enough, you get 3 of the basic ones for a cheap price. I would also buy the larger, more complex books in this series, your children will love them.
I already have the 'playbook' and 'squeaky book' in the same series. The pictures in the 'box of books' were very repititious with the books I already owned. In fact - in the 3 books in the box of books - there were only 3 images that were new - all others were repeated. My 7 month old loves the 'playbook' and 'squeakybook' they are much more brightly coloured and there is lots happening on every page. I would recommend them as a much better investment. I have given the box of books away.