Layout for all robes followed that adopted from the very beginning on the Victorian Centenary. Namely a 320 on printsheet, comprising four post office sheets, each 2 panes of 10 rows of four stamps. The 5sh and 10sh are of course in portrait (vertical) orientation and so the perceived (but not actual) layout is reversed to four rows of 10.
The same comb perforator was used Perf 13¼x13¾, introduced for the zoological coil sized stamps (modified). The first medium format stamps to appear with this perforation was the 1/6d Hermes of the same series and the NSW Sesqui .
Chalk paper printings of all values are immediately apparent when compared to against normal paper. The stamps are thicker with a more washed out, whiter appearance in the design.
In 1948 chalk paper was abandoned. In the 5sh value, an experimental tinted paper was tried and abandoned after a few months. As it was quite different in appearance it was collected, and not of great scarcity. Similarly, when normal paper was subsequently used, it too was collected and not at all scarce. (The other reason for very large quantities of mint 5sh robes in circulation was that they were a favourite form of payment. The lowest cash note was 10shillings. People would use mint 5sh stamps as note currency, particularly in letters.)
Shortly prior to the abandonment of chalk papers on the 10/- value McCracken introduced a new aniline ink. It is scarce, as it's effects weren't immediately obvious (unless you soaked the stamp off paper). The ink continued to be used for a very short time on a subsequent normal paper printing as well. Aniline printings, particularly with imprints, in both papers are very very hard to obtain.
The introduction of this ink coincided with new electros with authority imprints.
There was some snobbery associated with the use of chalk surface paper. It gave a much deeper impression. It was used on the 3d in the zoological series for a very brief time until it's poor printing properties (in volume) were discovered. The plates wore out more quickly, and it was not suitable for small, finely engraved designs. The 3d was the overseas letter rate.
The higher denomination robes series, also used for overseas postage (parcels) continued to use chalk paper because it was practical to do so.
A thin paper block qty:160,000 vs Thick paper 1M6.