The Mirka 21-101-P800 WPF Pro sandpaper sheets are waterproof abrasive sheets sized at 9 x 11 inches and packed 50 sheets per box. This is a sandpaper sheet designed for manual wet sanding and finish-stage surface preparation. Model Number: 21-101-P800. If you are sanding paint, primer, lacquer, metal, wood, putty, or composite materials and need a fine, polish-friendly finish, this sheet is built for that part of the process.

What matters here is not just the P800 grit, but how Mirka built the sheet around that grit. WPF Pro is described as a high-quality waterproof abrasive with a lasting aggressive cut, which means it is meant to keep removing material consistently instead of fading early. At this grit level, that translates into controlled refinement of the surface rather than heavy stock removal, making it a solid fit for primer sanding, topcoat sanding, and other finishing steps where surface quality shows up in the final result.

Mirka also calls out curl resistance and a non-absorbent construction. On the job, that matters because wet sanding sheets that curl or soak up water can get annoying fast and make it harder to keep even contact across the surface. The minimal suction to the surface is another practical detail. It helps the sheet move more smoothly by hand, which makes long sanding passes easier to control and reduces the stop-start feel that can show up with lesser wet sanding paper.

The C-weight latex paper backing is there for flexibility. That gives the sheet better compliance over contours, repaired areas, and curved panels where a stiff abrasive can leave uneven pressure marks. Mirka also notes a highly polishable scratch pattern, which is exactly what you want in a fine-grit wet sanding sheet. If the next step is polishing, recoating, or refining a finish, a cleaner and more uniform scratch pattern saves time downstream.

In terms of application range, these sheets are suited for paints, primers, lacquer, metal, composite materials, putty, and wood sanding. That makes them useful across automotive refinishing, marine refinishing, body repair, paint prep, and detailed finish work in the shop. The plain 9 x 11 inch format is straightforward too. You can use the full sheet by hand or cut it down to match blocks, pads, or the exact size you want for tight work.

This Mirka sheet makes the most sense for users who already know that finish prep is where a job can either come together or go sideways. If you need a coarse sheet for stripping, this is not that. If you need a fine wet sanding sheet that stays manageable, works across common refinishing materials, and is sold in a shop-friendly 50-count box, it is right in its lane.

Mirka 21-101-P800 WPF Pro Sandpaper Sheets for Clean Finish Work

This is the kind of sheet you buy when surface quality matters more than brute-force material removal.

• Who it's for: Painters, refinishers, body techs, and serious DIY users doing wet sanding on primer, paint, lacquer, metal, wood, putty, or composites.
• Why it stands out: The waterproof build, flexible C-weight latex paper, and polish-friendly scratch pattern are the details that make a fine-grit sheet easier to control and easier to finish out cleanly.
• Worth knowing: This Mirka 21-101-P800 WPF Pro sandpaper sheet is a fine P800 sheet, so it is for refining and prep, not heavy stripping or fast stock removal.

• What type of sanding is this sheet made for? It is designed for manual wet sanding.
• What grit is this Mirka sheet? It is P800 grit, which is suited to fine sanding and finish preparation.
• What materials can it be used on? Mirka lists paints, primers, lacquer, metal, composite materials, putty, and wood.
• What is the sheet size? Each sheet measures 9 x 11 inches.