Express Checkout - Change default image used.

[angelleye]

Right now we're using this PayPal hosted image for our Express Checkout button by default. This image does not look very good on many backgrounds, though, because the small text under the button doesn't come out well.

PayPal provides different buttons that can be used for checkout buttons in general.

I would like to use this one as our default instead of what we're using now: https://www.paypalobjects.com/webstatic/en_US/i/buttons/checkout-logo-medium.png