My pecs are thick from heavy bench presses and dips, but I don’t have any striations. Yet I’ve done hundreds of sets of crossovers over the last year or so. What’s wrong?
You could do thousands of sets of crossovers over many years and still see no striations in your pecs. Alternatively, you could no crossovers whatsoever yet still see striations. (Similarly, you could do countless sets of crunches yet never see your abs.) The key issue is your bodyfat percentage. No matter how large your pecs are, and no matter how many crossovers you do, if your bodyfat percentage is too high you will never see your pec striations. (Similarly, no matter how much ab work you do, if you have too much fat over your abs you will never see your six pack.)
If you want your pec striations to be visible, gradually reduce your bodyfat percentage to under 10% – sufficiently under to produce the required visibility.
Also don’t do crossovers thinking that they will build big pecs. They may help you to build some additional detail in your pecs, which you would see only if you are very lean, but they won’t build a lot of muscle, at least not if you are a typical, natural bodybuilder.