Tell me about your seeds

[gunrunner]

I have grown tomatoes for many years but have never saved seeds. Was wondering, do you notice any loss of plant quality after growing saved seeds? Also, I just watched a vid on youtube where a guy took and tomato cut it in half and rubbed it on a paper towel to remove the seeds. Then he let the paper towel dry for several days then folded it up and put it in a plastic bag to save for next year. Is this a good method? Looks fairly easy to me, just wondered if it would produce a good plant this way?

Thanks
Mike