If you are having your film supplied to you by an outside printer or graphics house you should specify, always, to have the emulsion on the top side, right reading. When you contact a film positive to a direct emulsion coated or capillary direct film screen you should be contacting the emulsion side of the film positive to the emulsion on the screen. You should not have the carrier sheet between the two layers of emulsion. A specific red or amber color spectrum will act just as if the image was totally opaque. Film positives produced with an inkjet printer must have enough density to be able to block UV light in order to properly expose an image.
Many problems occur when the image is weak.
Some printers are making two copies and exposing their screens with two positives on top of one another, in registration, to increase this density . . . Most desktop inkjet printers are using dye based inks which do not have the density of pigment-based inks. You can refill your current cartridges with Pigmented Inks to increase the density and eliminate the problems. B. Carrier Sheets - Mylar, vinyl or vellum. Mylar is the best carrier sheet for film positives.