Although the shadow mask worked, it had a number of practical drawbacks.

By the time the next set of presentations was ready, shadow mask tubes using one or three guns were available.

Development was abandoned when the shadow mask proved successful.

GE eventually improved on the basic shadow mask system with a simple change to layout.

Improvements in conventional shadow masks removed most of its advantages during this period.

The following figure shows how the shadow mask works:

They had filed a patent on their shadow mask system only a few weeks after Geer.

Their demonstration unit had eight more tubes than a similar shadow mask system, which at that time represented a significant cost.

Unlike a shadow mask, all of the signal eventually reached the screen, further reducing power requirements.

Therefore, it is important that the shadow mask is unmagnetized.

Behind his shadow mask his mouth nearly dropped open.

They might be forced to license the shadow mask system if they wanted to remain competitive.

They used long stretched metallic wires as shadow masks during metal deposition.

This degaussing field is strong enough to remove shadow mask magnetization in most cases.

Doming problems due to thermal expansion of the shadow mask was solved in several ways.

Bi-metallic shadow masks, where differential expansion rates offset the issue, became common in the late 1960s.

For this reason, Trinitron systems are easier to focus than shadow masks, and generally had a sharper image.

The shadow mask is a thin sheet of metal with thousands of tiny holes in it.

When the shadow mask expands, or "domes," the little holes go out of alignment.

Additionally, the lack of the shadow mask makes the penetron much more robust mechanically.

This leaves the shadow mask with a small and somewhat randomized field, removing the discoloration.

Several companies have also developed hybrid variations that combine features of the aperture grill and the shadow mask.

To counteract this bleeding of colors, some manufacturers include the invar shadow mask.

During development, RCA was not sure that they could make the shadow mask system work.

Lastly, the Trinitron display of the 575 was replaced with a cheaper shadow mask screen.