How to know how many stamps to put on returning package?

[Nirvanafan]

Hello guys I am new to this and I am sending out my first request to Nirvana's bassist Krist Novoselic. I am wondering how do I know how many stamps to put on my return package I am sending him? I would hate for him to use his own money or for it to not be sent back due to not enough postage.

Thanks,
Josh

[johnnylightninglives]

Your best bet if you want to be safe is just put on the amount you think you will need then add a couple of extra stamps for safe measure just in case you're light or if it takes a year or more to come back you will be covered for increases in postage. I live in canada and i always put 5 or 10 cents more than i need on in case it takes more than a year to come back and when i send to the u.s. I put on 1 or 2 more stamps than i probably need to just to be safe.