The essence of Table 3 is not simply listing Escher's 137 periodic drawings, but rather that of determining what Escher did to border his tessellations, or otherwise. On occasions, he chose not to have a border line, with the edges of the tile determined by the colour alone of the motif. Ideally, this would be a simple listing, but various factors militate against this:
Revised working, where the revision has obliterated the original, e.g. No.54, of October 1942 and April 1963
'Instructional' tessellation, e.g. 136
Imprecise outline
The following key applies:
Colour. Motifs are defined by their colour alone, without an 'extraneous' border line. Included in this category are black and white
Outlined. Motifs with a decided outline (albeit of different thickness), with a black line by default, with occasionally a different colour, as stated
Unclassified. Occasionally, it is not possible to place easily into the above categories. These I term as 'unclassified'.
2 Of different thicknesses
Page History.
3 November 2025. Upgrade from Classic Sites to New Sites. The conversion had left the table intact, but poorly presented. Previously, each row was equally spaced, but here, the text is 'dropped' below, e.g. 133. However, when published, this shortcoming is, to a degree, 'auto-corrected'! Also, there is a massive space between the table text at the end and the page history. This will eventually be corrected, but it will suffice for now. The table is best seen at the Internet Archive.
Oddly, no date was given for the compilation, in line with all the tables.