Experimental papers with varying alkylketene dimer load were prepared and characterized with respect to size retention, reaction and hydrolysis. The characterization was done by using extraction studies, in combination with X-ray photoelectron spectroscopy and gas chromatography. The surface energy of the produced papers was evaluated using the Good–Oss method. It was shown that by stepping up size additions, both the polar and van der Waals components of the surface energy are reduced.