Its watercolour month and we are busy laying lovely colourful washes. If you have the best paper and paints you are already giving yourself a super chance of capturing the lovely reflective quality of the paint. Its only with watercolour that the paper plays such an integral part. It reflects light (through the white of the paper).
Its confusing to know which paper to buy but my recommendation is this one:
Saunders Waterford: 300gsm (140lb) Not in High White
from Jacksons Art Supplies they sell it in single sheets and at the checkout I put in a request where they ask for the instructions to the team: Please quarter the sheets
Jacksons art supplies for this paper to order click on the link