A method of additively manufacturing a composite part is disclosed. The method comprises pushing a continuous flexible line through a delivery guide. The continuous flexible line comprises a non-resin component and a thermosetting-epoxy-resin component that is partially cured. The method also comprises depositing, via the delivery guide, a segment of the continuous flexible line along a print path. The method further comprises maintaining the thermosetting-epoxy-resin component of at least the continuous flexible line being pushed through the delivery guide below a threshold temperature prior to depositing the segment of the continuous flexible line along the print path.