KASHIDA: THE ART OF JUSTIFICATION
Kashida is a kind of text justification that is utilized in Arabic scripts, particularly as it is a cursive script. Whereas in Latin scripts, adjusting the space between letters allows us to justify the text, in Arabic the letters themselves are stretched. Note that Kashida does not require the text to be equalized with another piece of text – it can even be used on a single word to make it more aesthetically pleasing.
We can perform Kashida, by stretching the letters as mentioned, or by extending the cursive stroke that joins the letters. But there is a difference between these methods. The following illustration demonstrates some examples of a stretch (mashq) and extending (tatwil). Kashida covers both techniques, or either technique.
There aren’t many letters that cannot be stretched or extended in the positions outlined (diagram)
The following listed words are no possible to be justified using Kashida. The red cross signifies that it is no able to be justified; an orange cross means that it is not desirable, but possible if necessary (diagram)
In terms of best practice, it is better to stretch instead of extend where possible as it helps to prevent large white spaces in the text. That is, if it is possible to stretch as letter, do so, as lengthening would be unnecessary and cause an unappealing visual. For example, “Dâl” cannot be connected to other letters so would be impossible to extend regardless, and must be stretched. On the other hand, boxed letters can be stretched when they are on their own or at the end of a line, and are therefore useful.