Jam Jars with Lids (Welling DA7)

I'm running a children's craft session on March 21st and I need jam jars!
The standard 1 lb / 454g jars would be ideal, but I can still use larger or smaller ones.
If you're near Pickford Lane, so much the better - it cuts down on car use to come and collect them. But we can collect from further afield if necessary.
Many thanks in advance.