Available in 140lb (300gsm) NOT & EXTRA ROUGH and have 20 sheets per block, and the 200lb (425gsm) NOT & EXTRA ROUGH have 15 sheets per block.
All these blocks have a very stiff backing board for extra stability.
Suits my style of painting very well & easy to remove unwanted effects - Ken Bromley Bockingford Block 200lb Extra Rough 11"x15"