Bleed Through

One of the main concerns for making good science educational books is “bleed-through”, that is, how much of the page on the other side is visible.
We have seen very good science educational books been ruined by the huge amount of bleed-through which makes it harder to read pages. Every educational book has some amount of bleed-through. To completely eliminate it is not practical since pages would have to be either very thick or one would have to use very expensive paper with high opacity.
So, the concern is the degree of bleed-through. How much of the text and art on the opposite side is shown through? Should you have good answers, or what to know how we can deal with it, please ask us.