Although there were eventually 100s of commercial microscope slide makers known to have worked in England and on the Continent during the period from the 1830s to 1900, there was a relatively small group that could be considered pioneers or true masters of their art.  Prior to about 1850, these individuals produced much of the commercial quality slide output that was then available. Most were the actual preparers of the mounts they sold, developing and perfecting the new tools, skills, and techniques needed for their growing trade. Many also came to be highly regarded and respected within the academic and professional circles of their time. Several became successful business entrepreneurs as well, remaining in business for many years, and becoming widely recognized as experts in their chosen field. Others were content to pursue their profession in relative obscurity, leaving marketing to others.
As the demand for objects to supply the commercial slide market increased throughout the 1840s, so did the opportunities for others to become involved in the trade. By the 1850s, a growing number of individuals were becoming known for their microscopical preparations. While some were family members or associates of the early pioneering slide makers, others developed their mounting skills as enthusiastic naturalists and amateurs. Some of these talented individuals went on to professional careers as full or part-time slide makers, while others maintained purely academic or amateur status; mounting part time while continuing to pursue their primary trade or career. 
Please click on the names to the left to select and view the work of some of these acclaimed individual mounters. The order of the names is approximately chronological, with the earliest slide makers at the top.  One needs to bear in mind too, as their work is examined, that almost without exception, all of the slides shown were produced well before the days of electric lighting or modern indoor plumbing, and often in working conditions that we would regard as quite difficult indeed (**see interesting note below, beneath the slides image).
**H.G. Wells provided a vignette of "commercial" slide preparation in London circa 1888:

"I made my sketches under the Bloomsbury Dome and enlarged them as diagrams in a small laboratory Jennings shared with a microscopist named Martin Cole in 27 Chancery Lane. Cole, at the window, prepared, stained and mounted the microscope slides he sold, while I sprawled on a table behind him and worked at my diagram painting. Cole’s slides were sold chiefly to medical students and arranged upon his shelves were innumerable bottles containing scraps of human lung, liver, kidney and so forth, diseased or healthy, obtained more or less surreptitiously from post mortems and similar occasions."

  From   H.G. Wells, Experiment in Autobiography, 1934