Throughout the ages, rabbinical communal leadership wished to retain the professional services of excellent artisans while ensuring that their work conformed in every manner to halakhic standards. They chose to work only with those who could meet these standards.
Great halakhic works minutely detailed those laws concerning the writing of Torah scrolls and excerpts inserted in phylacteries [tefillin] and mezuzot, even detailing the shape of the letters and the various types of serifs.
One such example was Barukh še-Amar, a work by 14th century Ashkenazi sage, Rabbi Samson ben Eliezer.
This paper deals with some of the halakhic-paleographic issues mentioned in Barukh še-Amar, especially common errors made by scribes that can be identified with certain areas in Ashkenaz (such as Erfurt or Bavaria), which Rabbi Samson sought to correct.
The editions of Barukh še-Amar known today, even if they include illustrations, apparently had no access to scripts from Rabbi Samson’s time and place. Instead, they showed examples based on the scribal art known to the publishers in their respective situations.
We can conclude that in historical perspective rabbi Samson ben Eliezer was usually very successful at correcting scribal practices.