I used these great jars from Quickjars. I have to say they were well packaged and so spanking new - it was lovely to pot up some compote into brand new jars rather than some hastily washed ones that I have been keeping. So far, they have served me well and I still have masses to use.
Only........it didn't set. I used the Pam Corbin recipe from the River Cottage Preserves book - I know my daughter used it last year and the jam did not set. You need to boil it for longer than it says I think as this is not at all set. Not even remotely, so it has now been renamed Plum Compote. It is delicious on ice cream and last night we had roast apricots, mascarpone and a splash of the compote. It was amazing and I wouldn't have ever thought of using runny jam.
There were still some plums left over so I made three plum cakes from a random web recipe that I can no longer find. It contained ground almonds (but only 50g) and plenty of plums. The large cake needed at least ten minutes longer to bake and it was still a bit gooey inside - but we really don't mind this!
I was given the jars free of charge from Quickjars but I was free to write anything I liked and use them as I wished