Press F7 (or Edit menu) and select GRAPHIC EDITOR
Unique among editors, with DeePsea you can draw on any wall texture, sprite, floor/ceiling or other graphic following the Doom texture storage format. This includes many other graphic symbols, such as the fonts, logos and special screen display symbols. DeePsea automatically searches all lumps in PWADs to detect eligible names.
You can also draw on any FLAT floor or ceiling texture. They have a special storage format. DeePsea detects this type of texture by noting the lumps between F_START and F_END (or FF_START and FF_END). If you have grouped some new flats with your level and they donít show up in DeeP, use the Rename/Ins/Del/Move Pwad Lumps command in the Edit menu (or press F7) to either add these control elements or move the lumps around so they are follow the above conventions.
DeePsea supports the use of additional images by opening the files (PWADS) with the additional images. This is similar to the way DOOM supports additional images with the -file command.
Adding more Texture Names
DeePsea is the only editor where you can easily add new texture names and patches. Please review the help index (Graphics) and select the areas of interest. The easiest way to create new textures is to use the Auto Textures from BMPs selection from the F7 dialog (Automatic BMP to Texture conversion).
How to get a Game Palette to another graphics program
Save any graphic as a BMP or PCX and then open the file in your paint program. Makes it a snap to instantly match the palette exactly. You can also use the Graphics Editor to export a PaintShop Pro (PSP) format palette.