Spider Banking
See this post for more on spider bankers.
Open an account to hold currency
Initial account fee: 100p
Receive a unique lace tally of bewildering complexity that marks you as the account holder and is updated by the spiders on use. The pattern, scent, tension and gauge all convey meaning and make it almost unforgeable and unreadable my anyone other than a spider banker. The account is unreachable without it and anyone with it can use it. They will only issue one ever, but each time it is used they will "refresh" it by eating it and making it anew and updated.
Pawnbrokering
Will loan 25% of market value on anything.
Items are reclaimable for 25%+5% per session passed and will be claimed by the spiders once it passes 50%. No one is certain what they do with them, since they certainly don't sell them themselves, but they do sometimes return to circulation.
Receive a unique lace receipt. Only this can retrieve the item, losing it means never getting the goods back.
They know the value of things, intuitively, or so they claim. Either way they won't budge. They won't take clearly stolen items and will cooperate with the alcalde, saint cults, and all other arms of the Universal Congress in tracking down account holders for questioning. They won't return the goods without a lace receipt, but they may allow the wronged parties to pay your debt to claim your item if pressed.
Vaulting
Will vault objects for 100p up front plus 1% of their market value OR 10p (whichever is more) on retrieval per session held
Again, you will receive a lace receipt. The amount is payable on retrieval of the item in question. The bank hold these items, and accumulate interest, indefinitely. Items of dubious or sentimental value will be charged at the base 10p rate. Spider lace tallies or receipts are valued at their balance or repayment value. Similarly, stolen items will be retrievable by wronged parties given suitable evidence.
Lace Tallies and Receipts
They are of unmistakable origin, impossibly complex, uniquely scented, indecipherable by anyone with fewer than eight eyes, surprisingly tough, and worryingly flammable. Physically they are a thick golden doily-looking piece of lace-work with a meaningless (to you) asymmetrical design. The spiders make them as needed, at the till, in under a minute, spun from their own silk and knitted with their own eight hands. Every time the account changes they will eat the lace and make a new one reflecting the new status.
Possession of these is everything. They grant the bearer total rights to the capital associated with the lace and the bank will honour it without question. The spiders make it clear that matters of theft or rights are none of their business and you should take it up with the local justice.
You can hold three of them to a single inventory slot, but you probably shouldn't. While waterproof and resistant to cutting, fire will singe them easily and you will have to test your luck the next time you go to the bank to see if they will honour it. Any damage resulting in loss of material also requires testing your luck, and anything more than 25% loss will automatically invalidate it.