Could I use toilet roll instead. Kitchen roll is expensive!
Pfft, I just drop mine into a cup of water to soak until they get soft and puffy again - been doing it for 5 years. I keep them stored in their own sealed jar between runs.
You can also weigh them. They'll range 3-4 grams or more. You can measure when they're about to dry out, or if they're especially puffy.