This fabric tends to be restricted to Peacock & Williams Class 25, and associated with the later rim forms within this class. It is distinctive in its dense, very hard and fine appearance with a thick grey core and buff external surface. The surfaces are slightly rough and the fracture smooth. The colour of individual samples can be described as having a grey break or thick grey (6/0, 7.5YR 6/2) core, while surfaces and margins range between dull pink to red-brown (5YR 7/3–7/4, 2.5YR 7/6, 2.5YR 6/4) or dull orange (5YR 7/4–6/4). The external surface is normally slipped or self slipped to pale brown or buff (5YR 8/3–7/3, 10YR 8/3-7/3).
In essence, this is a finer version of BAT AM 1 with fewer inclusions. It is composed of a fine, calcareous and silty clay with sparse ill-sorted inclusions in a range similar to that found above, and it can be difficult to distinguish between the two. The sparsely micaceous (silver and gold) clay contains common silt-sized quartz and slightly larger limestone inclusions that are sparse to common. Larger inclusions are sparse and ill sorted, ranging in size between 0.1–5.3mm, although normally not exceeding 0.5mm. These comprise quartz, limestone, feldspar, and a range of red-brown and dark inclusions which are difficult to identify macroscopically but can tentatively be identified as metamorphic rocks, sandstone, clay pellets and ?opaques. As for BAT AM 1 large inclusions of limestone may erupt on the surface.
This fabric is similar to BAT AM 1 in the range of inclusions present, differing primarily in their frequency. It has a calcareous clay with a groundmass of fine-sand inclusions of quartz, limestone, feldspar and fewer microfossils. Common ill-sorted larger inclusions to coarse or very coarse sand are visible, comprising, in particular, limestone, quartz, mica schist, sandstone, feldspar, quartzite and shell. The clay contains sparse white and brown mica.