This is external to the water. What happens is over time any of this paper gasket material shrinks and hardens due to being exposed to temperatures approaching the max for the gasket material. This is why La Pavoni owners are always interested in how to tighten the boiler to the base and keep it tight. The paper material is not very resilient and once compressed it will stay compressed even if the clamp load is removed. The exception is the cork-rubber material. Using thin gasket paper on top and the cork-rubber between the base and clamp ring would be an interesting experiment.

This is for external boiler to base gaskets so no contact with the inside of the boiler. Mainly to keep the boiler from fusing to the base.

I may try the paper on the top and the cork on the bottom. I have time to test.

I have done some further sleuthing and talked with a molder here in Denver. The expensive part is the setup cost. They have to machine the die, making them is not that bad. Cost wise to get them around 80 bucks retail I'd have sell 200 of them .

Are you planning on making your gaskets for yourself or mass producing them for others? The reason I'm asking this is because I'm also trying to source out gasket materials for my LaCimbali M15 restoration.

I did come across a few alternatives, CalvoSealing (Spain) has a couple sheet style boiler gasket options, their ICP 9200 is currently used for espresso boilers and I emailed CalvoSealing about their higher temperature ICP 9400 gasket material but I'm waiting to hear back from them because I want to make sure it's food safe. From my research I've found that aramid fibers are safe, but the type of nitrile they use is in (my) question.
http://www.calvosealing.com/products/Co ... 9200/68/en

CustomGasketMfg also offers several different options for custom gaskets both flat and custom shaped.
http://www.customgasketmfg.com/DieCutGa ... ureGaskets

GarlockGasket (USA) also offers gasket materials in sheets available for purchase.
http://www.garlock.com/en/products/blue-gard-style-3700

I would try contacting these companies for additional options. I hope this gives you some alternatives?