A hidden insect screen system for tilt-to-clean, double hung windows whereby raising the bottom sash (104) causes resultant opening to fill with insect screen (115a) dispensed from an ordinary self-storing roller mechanism (114) mounted inside bottom rail (109) of said sash and whereby lowering the upper sash (105) causes resultant opening to fill with insect screen (115b) dispensed from an ordinary self-storing roller mechanism (122) mounted inside window head frame (103), all furnished such that vertical edges of the screens are protected from insect passage by contacting weatherstrip-like edge seals (127), and arranged such that insect protection is maintained with minimal interruption when each sash is tilted and its glazing is cleaned, the lower end of the upper screen being attached so as to be quickly repositioned from top to bottom of said upper sash.