The Knitted Knockers US website has a list of suitable yarns, which is reached through a link on their Frequently Asked Questions Page There is a separate UK site as well, who probably have a similar list but it if so it is in their members' section, which is only accessible to knitters who have joined.
Lighthearted - How long do you display Birthday Cards?
Are You Finding the Hot Weather is Making you Short Tempered?
Lest we forget what we have just lost ....
