In his hand was a small white envelope with a slit edge.

However, the occurrence of rough or irregular edges known as burrs are commonplace on slit edges.

The diffraction simulations also suggest that if the parallax barrier slit edges had a transmission that decreases over a 10 micrometers region, then crosstalk could become as 0.1.

Some involve each point of light generating light in all forward directions with interference from neighboring light eliminating all but straight-line light until the slit edges remove the neighbors.

Then cover the surface and apply heat as above, checking every few seconds as the glue softens; if the glue has deteriorated and does not soften, carefully scrape it out and insert a little carpenters' glue under the slit edges of the bubble with the tip of the knife.