The doctor blade must be held in perfect contact with the cylinder to achieve a clean, even wipe. The doctor blade holder is designed for this purpose. Doctor blade holders will vary with press type. Since doctor blades are thin strips of metal, they are often used with a back-up blade. The back up blade and doctor blade are clamped together in the doctor blade holder.
Holders can be either straight, curved or a clamping type.
Once the blade is mounted into the holder and positioned in the press, the angle at which the blade contacts the cylinder is critical. The best wiping angle is one that minimizes cylinder wear, wipes cleanly, and allows the greatest press speed. Two factors affect the blade angle. First is the angle on the blade itself. On beveled edge blades, wear may cause this angle to change.