Check boxes to hidden form printing

[#1]

Do you know how i would make it so when a box is checked it's added to a hidden list? Then i can make that list visible to print only.

I have 20 check boxes when a user picks boxes #3,7,9 and 12 I want only those will print on the form.

Keeps the printed form not looking so crowded with unchecked boxes. Please help, thanks.