Trial #4 - Four layers

I wondered if filling in the grid pattern with fine frit would change the gas-release pattern.

Trial #4 - Layers include blue streaker on the bottom, copper grid with star-shape cut out, clear frit, and topped with clear glass pre-kiln firing.

Although there is clearly gas released in this firing, as well, the pattern appears to be different than by simply sandwiching layers without the addition of fine frit.

Trial #4 - Layers include blue streaker on the bottom, copper grid with star-shape cut out, clear frit, and topped with clear glass post-kiln firing.

From a distance, the gathering of larger bubbles at the edges of the grid are visible.  Notice, also, that the bubbles are spherical, unlike the bubbles in the grid pattern in the previous post.

Trial #4 - Layers include blue streaker on the bottom, copper grid with star-shape cut out, clear frit, and topped with clear glass post-kiln firing.

On closer observation, not all of the grid cells have a bubble, but of those that do, these appear to all be spherical, as well.

Trial #4 - Close up of layers include blue streaker on the bottom, copper grid with star-shape cut out, clear frit, and topped with clear glass post-kiln firing.

Of course, there is no way to know with one trial if the difference in gas bubble patterning is a result of the addition of frit, temperature, type of glass, humidity, etc.   To learn more about the clear differences in bubble patterning would take more experimentation, but there is a clear difference!