Broken paint tube caps are the result of over tightening. Only screw the cap on half way - then STOP.
You don't need to tighten your caps to ensure that your paint doesn't dry out. Half a turn is more than enough to create a seal.
But as we are, we are bound to forget at some stage and sit with a broken cap. What do you do now ?
Use some cling wrap from the kitchen, put it over the unscrewed tube head and gently screw on the cap halfway.
Next time you have finished a tube of paint, and the cap is still fine, keep the cap. Clean it and store it. The next time you get the urge to strangle a paint tube cap, you will have spare one
