The Catholic church in the small settlement of Oberhof (sometimes mistakenly referred to as the church in Woelflinswil, whose parish it falls under) is a modest building with a hall-like interior, built in 1818 with funds from the parishioners themselves. The massive form of the building is more reminiscent of late medieval village chapels. The bell-turret on the roof was only built during restoration work in 1975. The church's main iconographic feature is the stained glass windows installed at the same time: in four windows of the nave and in two windows of the apse, flanking the Baroque high altar. The horizontal stained-glass panels (located in the centre of the vertical apertures of the nave windows, otherwise filled with neutral-coloured glass panels) depict the Nativity of Jesus, the Adoration of the Three Kings, the Flight into Egypt, the Carrying of the Cross, the Crucifixion and the Resurrection. The vertically composed altar windows, in turn, depict lone standing figures of Mary (left) and Christ (right) with cross nimbuses. Several of the stained glass fields bear the signatures 'Janczak Jan 74'.

This realisation was one of the first in Switzerland that Janczak created before he settled there permanently in 1981. At that time he was already associated with the canton of Argowia, in whose capital Aarau he also made stained glass. From then on, this field became one of the most important forms of artistic expression for the professor of the Academy of Fine Arts in Krakow, who was previously known mainly as a filmmaker and easel painter. Of all his works at Oberhof, Janczak's work is most closely related to the stylistics of late medieval stained glass. The artist makes extensive use of black, from which painterly shaded patches (or sometimes graphically outlined elements) emerge the shapes of grotesquely treated figures, trees, houses. Strong blues, violets and cinnabar, with a great richness of nuance, co-create paintings of an expression that rarely reaches a similar tension in the work of this painter, unique also in stained glass art of the time.