Let’s look at Kathy Reichs's first three suspense novels, Deja Dead, Death Du Jour, and Deadly Decisions. I like Kathy Reichs. Her writing reminds me of Patricia Cornwell's, only with more authenticity and detail, probably because in real life, Kathy is a forensic anthropologist. However -- and this is a big however for me -- each book she seems to pick one topic that she's going to tell you *all* about. In Deadly Decisions, it was the biker world and wars in Canada. Aaak. It was mushrooms all over again (see yesterday’s post). She also takes great care to get things right when it comes to procedures. Take blood splatters. She and another character go on for pages about velocity splatter and things like cast-off drops.
Here's a quote from one character:
The direction of the main axis of the ellipse with respect to the plumb line defines the directionality angle, or gamma of a stain. That can range from zero to three-sixty. The impact angle, or alpha, can range from zero to ninety degrees. That's calculated from the shape of the ellipse.Okay, I skip a lot when I read Kathy Reichs. But it's okay, because I know that if I don't want to read the details of how something works, I can skim to the end of the conversation and the two characters will tell me how it all relates to the plot. But, if you really want to know about blood splattering, this is the book for you. Incidentally, I passed these books on to my sister, who loves all that medical stuff. When we were kids, she was the one who wanted to be right there watching the doctor sew up your cuts.
So, how much is too much? And how little is too little? You're going to have to decide that for yourself. You can also let your critique group help you in this area. Read other authors; see how they handle these things in their books. Look to authors outside of your genre, too. You may write mystery or suspense, but you'll find writers of historicals have to explain terms or describe things long since forgotten. How do they handle it?
Maybe, instead of falling on the side of too much or the side of too little, you'll find a way to straddle the line. The trick is to find the best place to draw that line.