Injection moulding is a tricky business. The picture of the blue part is an early test moulding of our Pop Bumper frame and it clearly shows "wrinkling" or an uneven surface finish on the exact place it should be flat. This inside area is where the metal parts mount and ideally needs to be dead flat.

We inspected several parts from other manufacturers and found them to be much the same with the uneven surface finish causing some assembly problems.

The second test part (not in the final colour we will use) shows a part made with a plastic batch that has an additive that prevents this shrinkage in the finished part - MUCH better! It gives the part a pearl or slightly fiberglass look.

The assemblies fit together EXACTLY the same every time.