In a projection system a pattern plane on a reticle is illuminated to have a projection image focussed on an image plane. The tapered portion is cleaved or cut and polished to form a facet at which an optical beam is received or transmitted. A first closed cross-section is defined by the top wall, the left side wall and the left reinforcing member, and a second closed cross-section is defined by the top wall, the right side wall and the right reinforcing member. Additionally, with certain information related to the occurrence of suds lock, steps can be taken during the spray pretreatment portion of the cycle to avoid the condition of suds lock altogether.