I thought I'd try this technique as I've been meaning to do it properly for some time. You basically use a laptop screen set to bright white and fit a circular polarizer on your lens. The screen is also a polarizer and so your object, which is sandwiched between the two polarizers shows some unusual stress effects in hard plastic.
You need to turn the laptop upside down, as show in the shot below. Best way to get a white screen is to load Notepad on full-screen. Turn the laptop brightness to highest setting (but remember to adjust it back after shooting). Place hard plastic object on the screen, and when the composition is set just turn the polarizer disc until the white screen goes black. You'll probably find there's just a narrow section that makes it go black, but that should be enough. Your white screen is now black and the stresses in the plastic will show, as below.
In Photoshop RAW I boosted the colours very slightly (didn't need much), a bit of clarity, and slight levels adjustment. It didn't take much at all.
I used some very cheap plastic picnic cutlery. The cheaper the better, I think, as you want more stress in the material. Anyone have any suggestions for other objects to shoot? Soft plastic won't work. If you want to try it yourself, feel free to post here.