How do I make/ work on screen under custom.exe?

Well that's rather easy but it is a good thing to explain once more how to do

->make a basic screen ->go under custom.exe and import it as tileset ->work on it exactly as you do with map tileset.

This way to work is rather original but has several advantages

• You don't loose your bmp screens
• You know rather well how to work on graphics under custom.exe but not necessarily with a complex (and expansive) drawing programm like Photoshop or Paintshop Pro
• You are certain that there won't be any problems with colors
• You can rather easily take them back as bmp and jpg using a "backdrop point"