The present invention relates in part to a print method for an arbitrary grey scale image on a transparent substrate such as glass. The present invention makes use of a printer that can print in continuous grey tones. The printed material should be transparent and resistant to the light which passes through it in a projection system. The present invention also provides a continuous grey scale filter made by a printing techniques using liquid inks or toners. Such a continuous grey scale filter can be used for blending multiple images in a multichannel projector system. The present invention also provides a multichannel projector system using the continuous grey scale filter.