[a761506]

It looks like you only dipped the card in the bestine or kept saturating the corner area with a wet q-tip, which is why it is stained like that - total immersion is the only option when trying to work on a card with anything from water to the strongest chemicals, as it will ensure no stain like that - gotta take the plunge before all else.

Like I said with Bestine, you need to understand its purpose, and then you will quickly realize why it didn't work. It is for use with rubber cement. The adhesive on tape is a completely different chemical compound than rubber cement.

There are chemicals in tape that got released into the card beginning immediately after the tape was originally adhered to it. Those chemicals stained the card, and I do not know of any chemical solution that will effectively remove them from the card. Thus, a card with a tape stain will always have that tape stain. Not even a professional restoration service can remove tape stains from a card, I've inquired to all of the places and people that do restoration work on cards.

The problem with using Bestine in any application involving a card is that, aside from not be effective at removing anything that you're likely to encounter that needs removal from a card - it does not dry fast. Quick evaporation is essential in any chemical you would apply to a card. You don't want it peeling or bubbling the surface or further damaging the card because the card takes a while to dry internally.

The reason someone may feel they had success with Bestine and removal of something adhered to the card is simply because the adhered object came off. However, you could use just about any liquid, from water to wine, and if the adhesion will break down, it doesn't matter what liquid is used - the effect will be the same. The easiest way to think about this - an old postage stamp on an envelope. There are millions of cancelled stamps floating around, they have been removed from the envelope by simply soaking the envelope in water. The gum broke down in a matter of a couple minutes, and off the stamp came. The effect would be the same in any liquid.