My preference for books is always a hard copy, but sometimes having easy access to the information is more important than having a physical book, especially when copies of the actual book are impossible to find or really expensive.
That’s the case with this book, Plastering Plain and Decorative. First published in 1890, the book has become known as “The Plasterer’s Bible”. Now out of print, except for the occasional third-party reprint, it went through four editions. It contains hundreds of black & white photographs and drawings which aren’t always of a very good quality with most of the modern reprints, usually because they are printed in a smaller size than the original quarto size and because the scan quality of the original images is bad.
On top of not being of a very good quality, they are also nearly as expensive as an original copy, which would be a better bet as those are stitched like a traditional book and not perfect-bound (glued edges) like all soft cover books are. I have seen so-so quality reprints go from anywhere from $100 to $300.
Fortunately there is an inexpensive (free) copy of the book online at the Internet Archive. This isn’t just a book of nice drawings and photos, this is a book written for crafts people. Besides the layout diagrams, there are drawings of the actual tools used to create complicated plaster elements and a huge list of plaster types as well as the ingredients and mixtures used to create them in various time periods, such as instructions on what type of animal hair to use in the staff pieces for strength. It is an early edition of the book and contains over 700 pages which is more than is included in later editions.
The book covers not just typical plasterwork but, sculpting, mold making, terra cotta work, scagliola, sgraffito, and composite decorations. Besides Western European techniques it examines designs and techniques from Japan, China, India, Persia and the Middle East.
There is also a section on concrete work such as staircases, sidewalks, road, roofs, fountains, and other decorative elements.
You can find the digital book here at The Internet Archive. There are a number of different digital files available for download with varying file sizes depending on the quality of the images you want to have available.