masking fluid......

I have been tidying my art materials(!) and found my Pebeo fine masking fluid pen, (we probably used them a year ago, perhaps eighteen months?) tried it and of course it didn't work. Remember the instructions were to keep cool (its been in my conservatory) store horizontally (probably hasn't been) and know that the life of the item would be six months. Well I shook it vigorously, cleaned the tip, and pogo'd it up and down and guess what, it works perfectly.......so I hope yours still works too.....