The present application relates generally to photopolymer blends and related methods for use in an additive fabrication (e.g., 3-dimensional printing) device. According to some aspects, compositions are provided for the modification of a base photopolymer resin. The compositions may comprise colorant agent and/or cure-modifying composition. The compositions may be selected to cause, when combined with the base photopolymer resin to form a photo-curable composition, at least one property (e.g., color, depth of the cure) of the photo-curable composition to fall within a pre-determined range. Related kits and methods are also generally described.