I bought a full set of Geneva paints several months ago. Love the paint as I have heath issues an can not use solvents. I opened my paints today after working out of state and was surprised when I got very thin paint and a lot of clear liquid.. I tried to massage the tubes to put the liquid back into the pigment but that has not helped. How should I store the paints to keep this from happening? The yellow was very runney the blue was very stiff,as was the umber,the white and red was very thin and runney .What is the shelf life on the paint? Do Ineed to replace all my tubes ?