The spatial order of a pulli kolam is determined by the numerous dots which aligned in rows (varisai). In an idai pulli kolam, the dots are aligned in staggered rows; while in a ner pulli kolam, they are lined up in neat rows.
How to draw a pulli kolam
To draw pulli kolam, the dots can be joined with straight or winding lines, or the dots of a single continuous line can be circumvented with criss-crossing and intersecting lines. These dots can also be circumvented by several single or continuous overlapping lines. (See Sikku kolam or interlaced kolam).
The simplest way to draw a kolam is to take the powder between the thumb and forefinger, and guide it onto the ground to obtain a dot or a line. The pulli kolam, or dotted kolam, have many variations which range from the purely geometrical to interlacing lines, stylised representations of animals and plants, benevolent gods with their vehicles or attributes, and votive objects like oil lamps, or pots used for offerings.
The article is a translated excerpt from my book : VOYAGE DANS L’IMAGINAIRE INDIEN, Kôlam, dessins éphémères des femmes tamoules.