Whatman's is not as rough as Somerset, which gets very 'pebbly' after all the wet steps. I have been printing Whatman's on the "B" side, otherwise known as the back or screen side, and it is quite satisfactory for prints larger than 5x7. It is no longer available in the US, but I have ordered a stash from Ken Bromley Art supply in the UK, and even with air shipping to the US, the cost is still around 5.50 USD per sheet, which is comparable to Platine and less than COT320. The last time I bought 100 sheets to make the whole economics of shippping make sense.