By far our most popular material for a full cap is French lace with poly on the back and sides. It's comfortable, strong and undetectable. And it's great for the hot weather. Some people have used ILace which is hair that is 'sandwiched' between two layers of lace. It's also good and very strong. And the knots are well hidden. The downside to this material is that it doesn't 'breathe' as well as French lace. The two layers of lace don't allow the ventilation that French lace does. Tip: when making the template remember to mark where would you like the crown to be positioned (or no crown at all if that's your choice). This applies to both full cap templates as well as topper templates.
Regards,
John