I went to the J. D. Robb website and found pictures of all the covers of her books which I copied into a Word document. I then resized them to .4 x .6 then copied them into every third cell of a table that I had set up in 30 columns - 10 sets of 3 - back covers, spines and front covers. The spines have the titles running down then were filled with a colour I tried to match (more or less) with the front cover. I think I know why I ended up with the extra space below the covers but it worked to my advantage as some of the covers were slightly longer than others.
Here I had printed two rows of books on 65 lb. cardstock. I scored on both sides of the spines then cut out all the covers using a straight edge and scalpel.
The book covers were folded into shape.
Two strips of matboard were cut to the width of the book covers
then glued together and clamped.
The book covers were then glued along the matboard strip.
Once the glue had dried completely, I cut the books apart with my mitre cutter.
Here are 20 books - just over half of the series.
And here the books are in place in the bookshelf that I built into the wall.