Don't know. Gourds come in different species. Also the "hard shell"gourds (Lagenaria siceraria) are grown in India and southeast Asia as a food crop. I would expect that they would put a premium on a thin skin.

Here is a link that might be useful: Gourds

Thanks for the link, farmerdilla. You're right, gourds, especially bottlegourds are mainly used as a food crop and the thin skin is handy for that. But I use the round variety of bottlegourds (I'm sorry, they dont go by any other name here) for crafting and the thin skin is a disaster for that. I would have thought that when it is left to mature and dry the skin would also become thick but it doesnt. Would it have anything to do with the extra moisture during the monsoon season. Does anybody know?

I have no idea. There are round bottle gourds like Bhoomi which are grown for food. Calabash , birdhouse and like hardshell gourds are used for crafts in this country. The shells when dried are not necessarily thick but very hard. Not in the same class but Tinda is a small round gourd gaining rapidly in this country as an edible.

Here is a link that might be useful: Indian Gourds