size of swaddling blanket/sheet

[dancingvic]

Hi,
All the guides about how to swaddle I've read say use a cot sheet or blanket. The ones I've got are massive and too nice to cut up, so could someone advise me how big they should be for swaddling and where can I buy cheap ones?
thanks

I use recieving blankets from a brand called "Kushies". They are the perfect size...but I don't know if you have that brand where you live. I'm from Canada.

I bought some swaddling blankets in John lewis and they seem a perfect size.