An optical mask has a first pellicle attached. The optical mask is inspected with the first pellicle in place using first wavelengths of electromagnetic radiation. The first pellicle is replaced with a second pellicle. The first pellicle only allows the first wavelengths of electromagnetic radiation to pass, and the second pellicle allows second wavelengths that are shorter than the first wavelengths to pass. A photoresist is exposed using the optical mask with the second pellicle in place. The second pellicle is replaced with the first pellicle. The optical mask is again inspected with the first pellicle in place using the first wavelengths of electromagnetic radiation.