Only the door seemed to be made of opaque material.

He threw off caution and quickly cut a slot in the opaque material.

It shows that a light pulse can be focused in space and time despite having passed through an opaque material.

The lingering question for some of you will be, "How do you focus light through an opaque material?"

This is not possible with a sheet of ordinary opaque material.

Next, she'd have pinned up the sheet of opaque black material behind her, letting it hang to the floor.

Streak is particularly important as a diagnostic for opaque and colored materials.

He stroked a hand down the opaque material, and the stuff turned utterly transparent.

It may be smoked onto the surface of an opaque material to form an integrating sphere.

In some games, all of the opaque material is removed to see if the contestant has won, and how much.