It is a wall painting technique, made on a freshly laid plaster - the other type of wall painting is called fresco secco, executed on a dry wall, using lime or organic binders. The paintings in Pompeii are executed using a fresco technique (true fresco or fresco buono). (Pl.NH XXXV.120) Some of the best examples of Fourth Style painting come from the House of the Vettii which can also be visited in Pompeii today. In describing what we now call the Fourth Style, Pliny the Elder said that it was developed by a rather eccentric, albeit talented, painter named Famulus who decorated Nero’s famous Golden Palace. The Fourth Style also incorporates central panel pictures, although on a much larger scale than in the third style and with a much wider range of themes, incorporating mythological, genre, landscape and still life images. Faux marble blocks along the base of the walls, as in the First Style, frame the naturalistic architectural scenes from the Second Style, which in turn combine with the large flat planes of color and slender architectural details from the Third Style.

It can be best described as a combination of the three styles that came before. and is seen in Pompeii until the city’s destruction in 79 C.E. The Fourth Style, what Mau calls the 'Intricate Style,' became popular in the mid-first century C.E. The Roman architect Vitruvius was certainly not a fan of Third Style painting, and he criticized the paintings for representing monstrosities rather than real things, “for instance, reeds are put in the place of columns, fluted appendages with curly leaves and volutes, instead of pediments, candelabra supporting representations of shrines, and on top of their pediments numerous tender stalks and volutes growing up from the roots and having human figures senselessly seated upon them…” (Vitr.De arch.VII.5.3) The center of walls often feature very small vignettes, such as sacro-idyllic landscapes, which are bucolic scenes of the countryside featuring livestock, shepherds, temples, shrines and rolling hills.

The Third Style was still architectural but rather than implementing plausible architectural elements that viewers would see in their everyday world (and that would function in an engineering sense), the Third Style incorporated fantastic and stylized columns and pediments that could only exist in the imagined space of a painted wall. Example of Third Style painting, panel with candelabrum, Villa Agrippa Postumus, Boscotrecase, last decade of the 1st century B.C.E.

Gardenscap villa of livia