First, find something in there you don't mount, like elephants, for example. Hold the book open in your left hand, tear out that page and throw it down with your right hand. Ninety percent of the fish I mount are L.M. bass with an ocasional crappie or trout. I like Tohickon eyes. So I tear out all those Van Dyke eyes that I don't use, that alone will lighten the book by 4 lbs. 7 oz. I haven't gotten into the african thing yet. No game farms around here, they wouldn't fit thru my door anyway so out they go. Basically, just tear out any thing you don't use. I have another one in case I get 5 calls tomorrow wanting elephants done. My catalog is only 1/4 " thick. Another method is to hang it in the outhouse like the sears catalogs back around the turn of the century. I used to antique alot, anybody ever see a Sears cat. from 1800? It makes the Mck. Cat look tiny. I wonder if an old cowboy ever walked in to the old dry goods store and ordered some britches and said, " dern catalog's too thick, need a forklift to get it off the counter. LOL!