Right now the exchange rate for American dollars into Canadian dollars is very favourable.
For example, on December 26, 2015 VISA USA posted that it cost only $7.39 USD to buy $10.00 CAD worth of goods, (even if you're bank is charging a 2% foreign purchase fee).
That's like getting more than a 26% discount.
This means your dollars are worth that much more when you buy from a Canadian online fabric store. Exchange rates fluctuate so if you want to know what the current rate is, please check with your bank, Paypal or your credit card provider, but while the Canadian dollar is low, it's a great time to stock up.
Remember prices on the site are shown in Canadian dollars, if you're shopping with a US credit card or Paypal account, they will calculate the exchange when you make your purchase.