An apparatus for exposure of a relief precursor includes a substrate layer and at least one photosensitive layer. The apparatus includes a first light source configured to illuminate a first side of the relief precursor, a movable second light source configured to illuminate a second side of the relief precursor opposite the first side, a movable shield located between the first light source and the second light source and configured to capture at least a portion of the light of the second light source transmitted through the relief precursor, and a moving means configured to move the movable shield simultaneously with the second light source.

A pattern-forming method comprises applying a chemically amplified resist material on an antireflective film formed on a substrate to form a resist material film. The resist material film is patternwise exposed to ionizing radiation or nonionizing radiation having a wavelength of no greater than 400 nm. The resist material film patternwise exposed is floodwise exposed to nonionizing radiation having a wavelength greater than the nonionizing radiation for the patternwise exposing and greater than 200 nm. The resist material film floodwise exposed is baked. The resist material film baked is developed with a developer solution. An extinction coefficient of the antireflective film for the nonionizing radiation employed for the floodwise exposing is no less than 0.1. The chemically amplified resist material comprises a base component and a generative component that is capable of generating a radiation-sensitive sensitizer and an acid upon an exposure.

An apparatus for exposing a printing plate including at least a front source array of LEDs that emits a radiation field incident on the front side of the plate and a back source array of LEDs that emits a radiation field incident on the back side of the plate. A controller connected to the front source and the back source causes movement of at least the front radiation field relative to the plate fixed on a substrate that receives the printing plate in a fixed configuration between the front source and the back source. The apparatus commences a first exposure step of one side of the plate with one of the sources and then a second exposure step of the opposite side of the plate with the other source, imposing a user-definable time delay (t) between commencing the first exposure step and commencing the second exposure step.