According to Jeremy York, Tinker's work, along with his colleague Donald G. Paterson, "was a driving force behind the standardization of the print industry in the United States".
[8] His work focused on studies of typographic variables, seeking "variations in reader function as a response to typography."
This work has been updated with minor changes in 2018 and placed in the public domain (Amazon) for education and extended understanding of Tinker's lifetime of research, not only on typography, but also in psychology, illumination, eye movements, and reading.
In fact, Tinker's work did not as much define typography for printers as it standardized such variables for non-printers to learn and understand.
It is also suggested that Tinker's work would ably serve as a starting point for those who were interested in the effects of transmitted light of today's computers and how the wide variations possible effect reading and even attention on today's technological devices of all kinds.
Comprehension was an integral part of the test design, so that readers could not read any faster than their processing of the visual information within the text would allow.
Dr Donald Paterson was invaluable in adding statistical expertise to pursue the maximum reliability of analysis.
His study on Illumination suggested that brighter lights in the work area than the surrounding causes eye fatigue; instead, 25 foot candles would have been sufficient.
"[2] "Over half of Tinker's studies involving typography were co-authored by Donald Paterson, whose interests were aligned with those of present day instructional technologists.
"[13] Tinker's most important book was Legibility of Print, which summarized much of the research he conducted during his 32 years at the University of Minnesota.
[14] It is "the seminal study on how we read printed type, and it remains the standard for typography even now," decades after it was published.