Let us suppose I made a dungeon map I want my players to explore. How do I feed them bit for bit without revealing the whole dungeon?

"Back in the days" I used to cover parts of the map with blank sheets of paper. It is probably the easiest solution but comes with significant disadvanteges. A light breeze can ruin the suprise as well as dark areas can shine trough.

Since VTT and letting the players draw the map themselves are no options I need a new idea. Maybe I will cut the map room for room and hand them to players as they discover new areas.

Any preferences?