Natural fiber welding is a process by which individual fibers are swollen by an appropriate ionic liquid-based solvent system to form a congealed network. Manipulated fibrous materials may be either composed of natural polymers such as cellulose, hemicellulose, silk, et cetera, or synthetic polymers, or mixed materials. The process is principally controlled by the composition of the solvent system which includes an ionic liquid solvent plus additives such as water, methanol, et cetera. Other conditions such as the amount and placement of solvent, as well as time, temperature, and pressure control the extent to which neighboring fibers are fused. Only the material at the outer surface of fibers need be sufficiently mobile to merge with that of neighboring fibers. Material in the fiber core may be left in the native state by controlling process variables. Fibers form a congealed network upon removal of the ionic liquid-based solvent.