Lately, I have been working with Ming editions of Zhuge Kongming Xinshu 諸葛孔明心書, a military text attributed to Zhuge Liang but which is most likely an early Song forgery. The earliest edition I was able to inspect was a moveably type booklet from Zhengde 正德 13 (i.e. 1518) at the Shanghai Library. Unfortunately the price for copies or scans was 100 yuan per page so I could not afford to make a copy. Yet even while at the library, I noticed that there were lots of vulgar character forms, some of them completely unattested. So when I found a facsimile publication of an edition from Jiajing 嘉靖 43 (i.e. 1564), I decided to look at these suzi in more detail. Of course, these unorthodox forms are not particular to this text, there are just as many of them in printed copies of other texts from the early modern period. They are a peculiarity of print culture of this time period and should be studied on a much larger scale, in hundreds of books together.
An early attempt to gather the vulgar forms — amidst the intellectual campaign directed at the simplification of Chinese writing — was a work called Song-Yuan yilai suzipu 宋元以來俗字譜, compiled and published in 1930 by Liu Fu 劉復 and Li Jiarui 李家瑞 on the basis of twelve popular (minjian 民间) books printed during the Song-Qing period. Of course, twelve books is a fairly limited corpus, especially since they come from an 800-year interval.
In any case, my own study is even more limited as I used a single text and gathered only about 500 different characters with some 2,500 concrete examples. Apart from the general impression that there is an incredible number of non-standard forms, the most surprising thing is that the same character is often written with orthographically different forms. This is of course not true for the majority of characters but there are still plenty that have two or more structurally distinct forms. Below I only list a few of them that are graphically different from each other (not all examples are).
Of these the character 懼 (ju ‘to fear’), for example, appears in its standard orthography, plus one that is today its simplified form: 惧. The same is true for the characters 辭 (which has three distinct forms), 後 (always used in thesense of ‘after’) and 並. The vulgar forms of other characters, such as 從 (cong ‘to follow’), do not match modern simplified characters. In addition, there are also lots of characters not included here that appear in the book only in their vulgar form and their standard form is never used.
What do these variations tell us? That even though we are looking at printed culture, which in our minds is often associated with an increasing level of consistency, in these minjian publications we do not see any sign of moving in that direction. Perhaps the study of shanben prints would lead to very different results, but the truth is that these popular publications comprised the overall majority of printed books at any given period. In this sense, they are more representative of how people wrote or what degree of graphic consistency was tolerated in their daily application of writing.