I find 45 degrees too steep I like it at about 20 degrees just propped on another book. When I'm on the go I just have it flat on the table, my thigh or resting against the bookshelf I'm standing at as I turn the pages. If the book will take longer than 4 minutes to flip I'll prop it. I find the biggest strain is in the shoulder when it's on a desk... one of my reasons for preferring the thigh most of the time. I can rest my arm on the armrest of the chair taking the load off.
Alex
