If you are looking for for posters or printing based on the film Lyle, Lyle, Crocodile , the industry standard for a "deep" or premium feel is 10.4 mil thick luster paper . This weight provides a sturdy, professional finish often found in commercial film posters.
If you meant "deep paper" in the sense of a , 📚 Deep Analysis & Study Resources
: You can find a comprehensive Classroom Study Guide from Viterbo University that covers Bernard Waber's original book series and provides educational activities.