Mainer's works first became known through his participation in unofficial studio exhibitions called Confrontations. Since the beginning, his works have been influenced by spirituality. However, the subjects gradually shifted from Christian traditions of Baroque churches through Indian gods to magic. The depth of the picture is as important for him as is the way in which he expresses it. He often uses atypical materials which are related to the place of his inspiration. For instance, paint made from alpine rocks or foam torn so that it is reminiscent of worn marble floors in Italian churches.
Lodě na obzoru II., 1992, olej na plátně, 210 x 290 cm
Bez názvu, 1991, olej na plátně, 140 x 162 cm
Duchové, 1990, olej na překližce, 117 x 166 cm
Libušin soud, 1993, reliéf na reprodukci, 50 x 70 cm