Just cut to size and slip a piece of white (or other corresponding color) paper, tag board or plastic in there before you fill it. Then when your recipient uses what's inside, they can take the lining out to display the jars empty if they want. That'...
Kurt packed 24 jars,.. he figured he'd fill the top box in the stack and leave the other 8 boxes empty,... this way he could stiff the buyer and make a sweet buck...
If the jars are hot and the water cold, or vice versa, that will cause them to break. Also, if they have any hairline cracks to begin with, that will also cause it. Inspect the jars for cracks before filling them, and then I heat mine in the dishwash...