Based on the output and associations of John Rastell, and later his son William, these two men ran what can be described as the first "humanist" press in London (41). Their production of playbooks provides key insight into the almost certain relationship between playing companies and print houses: 1/10 of the books John printed were playbooks, and William doubled the number so that 1/5 books he printed were plays (42). Wynkyn de Worde, who based on Short Title Catalog numbers produced over eight hundred books, printed only three playbooks: Hyckescorner (STC 14039), The World and the Child (STC 25982), and The Interlude of Youth (STC 14111), and as the title of the last of these implies, these are all more properly described as "interludes" than plays (41 - 42). A comparison of the relative output of these printers suggest a deliberate choice on the part of the Rastells, and probably a relationship between the authors and the printers (42). This further suggests that authors wrote their plays conscious of the fact that they probably would be printed (42).
By the time printing had been introduced to London in 1476, the development of the print industry over continental Europe had inspired new scholarly efforts in procuring and preparing the best possible manuscripts of Greek and Latin works for printing. Early Italian humanist scholars had already started collating these manuscripts and employing sophisticated editorial methods, which ultimately led to new translations and editions of the complete works of Plato, the proof that the Donation of Constantine was a forgery, and to the correction of the New Testament. These practices would be introduced to London via Desiderius Erasmus and his friendship with Thomas More (42 - 43).
One of the ways in which Erasmus' editions rose to prominence throughout Europe was his use of fellow humanist scholars as editorial assistants to help him collate and correct manuscript texts (43 - 44).
Erasmus pursued textual accuracy and believed himself capable of recovering "authorial intentions," but also recognized that editorial intervention with a text could never be simply reduced to simple mechanical reproduction, which could not produce "true readings" (49). In this way, Erasmus foreshadows the modern editor if his own, and of Shakespeare's works. Simple mechanical reproduction is not sufficient to create a "true reading" of a text because that true reading requires the interpretation of the text in its narrative, cultural, material, and linguistic forms.
Extant paratextual materials related to the four printings of Utopia reveal that Thomas More studied Erasmus' editorial practices and attempted to emulate them (49).
Erasmus was such a close collaborator of More on Utopia that he seems to have helped coordinate the printing of all four editions, and to have prepared More's manuscript for the press (51).
More imported Erasmus' editorial techniques and focus on textual accuracy from continental Europe, but it is noteworthy that he also brought these techniques to his printers, John and William Rastell (55).
More was exacting and detailed in his instructions to his printers for the preparation of his manuscripts into print. Pynson, one of More's early printers, complains that, after the whole work had already been printed, he had received a newly emended copy from More, and had to re-set the entire book (56).
More sees in the process of perfecting his manuscript copy for print the advantage of editorial review, and finds the process of print gives more control over authorial intentions than manuscript circulation, which leave the work open to annotation by other hands (57).
In The Debellacyon More has printed a four page apology to the reader explaining a textual error that he missed in the perfecting process. He enjoins the reader not to blame the printer, prints the misprinted section, and proceeds to explain that this is due to him recording the wrong tense of the word initially. It is a devotion to textual accuracy that reveals his commitment to the print process (58).
Partially because dramatic works were coming to be valued by humanists as pedagogical tools in schools and universities, the Rastells applied the same diligence in preparing playbooks for the press that they did their other works, including More's (59).
While the early texts prepared by the Rastells, such as Fulgens and Lucrece were good, they were not perfect, and the sole existing copy of this play book displays the work of an annotating reader in correcting irregularities in the text, and even adding a missing syllable to complete an otherwise short stanza (62).
Massai establishes a tradition of relationships between printers and authors, including the authors of plays, going back to the early years of the London press. It seems an important distinction that the Rastells treated their playbooks as they did more serious works, but I don't think it's possible to say that all printers would have necessarily followed suite. Also, the quality of the printed book seems to have been in part determined by the oversight of a singular author intent that the work should reflect his intentions (as in the case of ore), and Massai herself notes that the collaborative authorship practices of dramatic writing were not necessarily conducive to this (64). While Massai establishes a tradition, there may be no way of knowing if that tradition was still being followed a century later, or even how it was followed in Johnson's print shop.