The sacristy is said to be the artistic treasure of the monastery. The pictorially decoration which accrued in 1715 and 1716 was created by Johann Cyriak Hackhofer.
The walls of the sacristy are decorated with scenes from the passion of Christ. The paintings show the foot washing, the last supper, the blood sweating, the castigation, the coronation with the crown of thorns, Jesus carrying the cross and the crucifixion. The last five paintings are the five mysteries of the achier rosary.
The common opinion is that these five pictures had not been painted by Hackhofer himself but under his guidance by some of his disciples. The basic of the walls is tessellated with cupboards and panels of nut wood with filigree inlays of tin.
On the ceiling Hackhofer created the painting of the Last Judgement. It is also known as the “Heaven and Hell” painting. It starts at the eastern part of the sacristy with the bright exposed heaven and the glorification of Christ. In this part Jesus is sitting on a rainbow circled by a corona of golden clouds. Outside the corona Hackhofer had painted a lot of saints from the Old (on the left side) and the New Testament (on the right side). The more the eye of the observer moves to the westward wall, the darker the colours and the scenes are. The sacristy is losing its natural brightness. The angels are carrying the tools with which Jesus had been tortured. The cross is pointing towards the western wall like an arrow. Tawdriness flashes jerk out from dark thunderclouds. In the end of the ceiling and the beginning of the western wall the colours change into red and brown and the picture shows the abyss to hell.
This “Fall to hell” painting is Hackhofers best-known work of art. It is full of symbolism. Lots of the tortured people stand for one human vise. The man with the treasure chest whose heart is eaten by a toad stands for avarice and greed. The masks are a symbol for falseness and pretence. The couple with the mythical creature that looks like a goat stands for adultery. The chicken on a spit held by a hand is a symbol for gluttony. For murder stands the bloody dagger. The person with the peacock feather in the hand represents pride. The dice and the cards depict gambling and the woman with the bracket on her tongue stands for garrulity and slander.