We present an experimental study on transformation processes in peapods. Local and quick annealing of freestanding films as well as conventional annealing in the furnace are applied. Raman spectroscopy and transmission electron microscopy are used for characterization of the samples. While laser irradiation beyond the optimum transformation of peapods into double walled carbon nanotubes effectively removes the formerly formed inner tubes, too hot furnace annealing preserves the inner tubes but causes the outer nanotubes to coalesce with each outer. These differences are due to resonant photo processes that render laser irradiation and furnace annealing complementary means of tailoring carbon nanostructures. (c) 2005 Elsevier B.V. All rights reserved.