I have attached an Excel spreadsheet containing tarp information from manufacturers' websites. For the most part, the manufacturers are those included in the list on this forum. (I will be happy to add any manufacturer not included if someone will point me to the relevant site.) I did not attempt to include every tarp in a manufacturer's product line, but rather only a representative sample, with a particular focus on ridgelines 11' and longer. When the material was not specifically stated by the manufacturer, I left that field blank; although, it is probably silnylon except maybe for two of the DD Hammocks.
There are a number of reasons why the information in this spreadsheet might not be that useful. First, I did not attempt to include columns for every important feature or option, e.g., the number of tie-outs is not included. Second, square-foot calculations are somewhat overstated for, e.g., hex and cat cut styles. Third, old timers - I mean *experienced hangers* - probably know all of this information in their gut already. And, some other reasons in addition. But maybe it will be of some use to newbies.