Do you think retail stores intentionally use disappearing ink on receipts so that when customers take them up on merchandise warranty, the store can easily deny them because they have no receipt or at least it's not visible?

I've noticed several of my receipts the print is barely visible and these receipts are only a year old. I've decided that I should at least scan them for archive so I have some sort of proof. I can at least use copies for manufacturer warranty.

My problem is I bought extended store warranty. So I do need the original receipt to bring to the store.

Credit Card statement or other proof is sufficient in the UK. Its probably the same in the USA. Also, there is no disapearing ink used, and what you are refering to is thermal printing (same as for some fax copiers) which does fade over time. If the store is aware that it uses this type of printing for its receipts, then I can't see how they can not accept your claim as they will have store records, and if they issue receipts that fade, then they will be aware of the issue. Goods can normally be tracked by their serial numbers, especially if an extended warranty was issued against that item.

Depending on where you go, I"m sure the store has your file online of what you have ever bought from them. Especially if you got an extended warranty from them, they should have a file.