1. Splice the truss according to the background size of 5×3 and the requirements, then cover the finished spray-painted cloth on the truss, and firmly fix the periphery of the spray-painted cloth on the truss with a pull rod.

2. Wipe the ash layer on the painted surface with a clean wet towel or linen cloth, and then several workers will erect the truss evenly and forcefully, and install a counterweight at the root to ensure that the truss will not shift or collapse due to external force.

3. Finally, according to the specific situation, it is judged whether it is necessary to cover the exposed part of the truss with black flannel, thus completing a complete truss painting.

Truss is a kind of supporting beam structure, which is welded, riveted or bolted, and its two ends are hinged. The advantage of truss is that the members mainly bear tension or pressure, so as to make full use of the strength of materials and save materials, and reduce the dead weight and increase the stiffness compared with solid web beams when the span is large.