Art collectors, galleries and more knowledgeable buyers tend to avoid photo-offset prints for this reason. The serigraph has become popular only recently, within the past few decades. A limited number of artists create a separate screen for each individual color. Each color is then printed, one color set a time, onto paper. The process does allow for the depositing of heavier amounts of ink and does allow for some texture.
Color fidelity is generally good.
However, the silk screen dots inherent in serigraphs have a tendency to break up fine detail and make some colors unachievable. While acrylics and oils reproduce adequately, pastels and watercolors generally lack the suppleness and softness of the original art work. This process is quite expensive on a per-unit basis. There are no halftone or screen dots that break up fine detail and lower the perceived value of the print. Color separations are made by hand to achieve the highest possible quality.