Fiberglass Mat Weight

I see plenty of threads about "How many layers should I use?" and generically it 5-7 and >= 3/8"s thickness, but no one ever mentions the weight of the mat or cloth. I have been using .75 and 1.5 ounce mat but to get to ~.25" it has taken about 6 layers, maybe more. So I have to ask what weight mat/cloth is being recommended for 5-7 layers and a thickness > 3/8's?

After doing a bit more refined a search, I found one post that recommended 8oz.

In boat building we use multiple layers which are offset arround 35 degrees from the previous layer. This provides additional strength. I don't think, however, that in this instance you would see any real benifit. Stormshadow

most people use 1.5 oz because it is the easyiest to find.......the thickest i would use is 3 oz. even that can be hard to bend in certain contours and corners. the thicker the mat the more difficult to soak it all the way thru.

Audiomechanic, how many layers of 1.5 would then be needed for reasonable thickness. I've been using 1.5 and roughly 6 layers amounts to about a 1/4" which seems to be contrary to what many here say. So then are we talking ~12 layers rather than 6-7 for a reasonable non-flexing enclosure. Correct or incorrect?

So defective 6 layers of 1.5oz + lets say about a centimeter of duramix is sufficient for a solid fg enclosure. I continue to ask because my first attempt has been reasonably successful but thickness is questionable and I'd hate to have to start again due to the glass being to thin.