Apparatus and process for forming a printing form having a cylindrical support

A process for forming a printing form from a photosensitive element comprising a cylindrical support and a composition layer on the support opposite an interior surface of the support, the composition layer capable of being partially liquefied, comprising:

• supporting the photosensitive element by contacting a first part of the interior surface of the cylindrical support with a first support member, and by contacting a second part of the interior surface of the cylindrical support different from the first part with a second support member, wherein the cylindrical support has one or more unsupported parts between the first part and the second part;
• and
• treating an exterior surface of the photosensitive element opposite the support to form a relief surface.