This article investigates the possibility that e-journal collections can reach a maximum size that satisfies long-term patron needs without further significant expansion. The study included collection and usage data taken from 2000 to 2013. In terms of the e-journal collection, the occurrence of a maximal mass appears to be very real. The e-journal collection has well-defined critical and maximal masses. The maximal mass of e-journals stands at approximately 25,000 unique titles.This article presents the results of a quantitative investigation explored the possibility that an e-journal collection can reach a maximum size sufficient to satisfy the long-term needs of an academic community. Once this theoretical mass is achieved, usage levels will remain static, even after further increases in the number of e-journal titles. In other words, usage levels will no longer increase as the collection continues to grow. This study included data from the e-journal collection available at the J.N. Desmarais Library of Laurentian University. 1 The number of e-journals was compared with the number of full-text articles downloaded. The analysis covered a 14-year period in which data were gathered from 2000 to 2013, inclusively.In a time of limited or decreasing acquisitions budgets and rapidly expanding eresource availability and demand, understanding the concept of a maximal mass and estimating its value can prove vital for any library intent on practicing responsible collection development. The detection of a maximal mass would provide libraries with the quantitative means necessary for the formulation of policies dictating collection management. Why continue to purchase or subscribe to large and expensive packages of electronic resources ©Alain R. Lamothe 1 Laurentian University (Sudbury, Canada) is classified as a medium-sized multicampus university. Total 2012 full-time student population was 6,863, of which 403 were enrolled in graduate programs. In addition, the total 2012 part-time student population was 2,652, with 428 enrolled in graduate programs. Also in 2012, the university employed 399 full-time teaching and research faculty members. Academic programs cover a multiple of fields in the sciences, social sciences, and humanities and offer 60 undergraduate, 17 master's, and 7 doctoral degrees.