I don't collect cards but have needed to remove stickers from plastic surfaces. What I have found that works best and is safe for plastics is Baby Oil, use it to remove the gum, then Windex to remove and oil left. Other remedies are (mentioned earlier)cooking oil, lighter fluid, lamp oil, or a host of other commercial products. Careful not to use anything abrasive on the slick plastic as it will leave fine scratches.

If in doubt or have an item that is sacred to you FIRST try the remedy (also mentioned earlier) peel the sticker, then use the sticky side of new tape to 'pull off' the remaining gum. This works but sometimes takes a while, especially if the old glue was ever hot (left in the car during summer).

Cleaning Chips: I use a light spray of Windex a small toothbrush (wife's)then rinse & dry. The toothbrush will get the grime out of the 'Hat & Canes' and will remove the dirt & film from all the table play. You should always use caution as to which chips should be cleaned or not and with what cleaner. Some chips are better left 'as is'. Some cleaners WILL degrade color or abrade the surface.

That's my 2 cents. (more like a dime! )

Mike