Cosmas 5 Pack B-112SN Satin Nickel Cabinet Hardware Knob Backplate/Back Plate

A small piece that makes a big difference

I picked up these Cosmas backplates to clean up a few tired cabinet fronts and to keep fresh paint from getting rubbed by fingertips around the knobs. They’re simple parts—satin nickel plates that sit between your knob and the cabinet surface—but they do two jobs well: they dress up the hardware, and they take the daily abuse instead of the wood or paint.

Build and finish quality

Out of the pack, the finish is what stood out first. The satin nickel is even, not too shiny, and consistent across all five pieces. The edges are clean with no burrs, and the mounting hole is centered and true. They feel like proper hardware, not a flimsy add‑on.

Cosmas lists a “High Quality Satin Nickel Finish,” and that checks out in use. I intentionally installed one on a bathroom vanity that sees a lot of hand lotion and moisture; it wipes clean without blotching or rainbowing, and the satin sheen hides fingerprints better than polished finishes. After several weeks of daily use, I don’t see finish wear or scratches.

Size, coverage, and fit

These are compact backplates, with an overall footprint of 2-3/4 inches long by 1 inch wide. The flat seating area (where the knob base rests) is 2-1/2 inches by 3/4 inch. That scale is important for two reasons:

• Coverage: If you’re trying to hide small rings of wear, minor paint peel, or hairline checks around an existing knob hole, the plate covers that well. If you’re dealing with oversized damage or an off-center patch from a previous pull, measure carefully—the 1-inch width is modest. For most scuffs and halo wear from hands, it’s enough; for large chips, you may want a wider backplate.

• Knob compatibility: The 3/4-inch flat width accommodates most standard knob bases comfortably. If your knob has an unusually wide or domed base, double-check that it seats fully on the flat area. Every knob I tried—simple rounds, a square post, and a small mushroom—sat flush and tight.

Visually, the proportions work best on doors and drawers 10 inches and wider. They don’t overwhelm narrow rails, and they add a subtle “finished” element that looks intentional rather than decorative-for-decorative’s-sake.

Installation notes

Installing these is a five-minute job per knob, provided you check screw length ahead of time. The backplate adds material thickness between the knob and the door, and that can make your existing screw just short enough to be annoying. In my case, two knobs with already borderline screws needed a 1/4-inch longer replacement. If you’re upgrading painted MDF or thicker drawer fronts, plan to have a small assortment of machine screws on hand.

My process:

1. Remove the knob and clean the area. If paint is flaking, feather it lightly so the plate sits flat.
2. Center the backplate over the existing hole. I like to use a piece of painter’s tape as a hinge to keep alignment while I thread the screw.
3. Reinstall the knob through the plate and tighten until snug. Avoid over-torquing; you’re clamping the plate, not bending it.

That’s it. If you’re working on a bank of doors, use a small combination square or a simple alignment jig to keep all plates level and at the same height. Consistency is what sells the upgrade visually.

Day-to-day performance

Functionally, these do exactly what I hoped. On a painted kitchen door where hands naturally grab near the knob, I used to see the finish dull and spot over time. With the plate in place, the contact happens on metal. The satin surface doesn’t show micro-scratches easily, and a quick wipe with a damp cloth brings it back.

There’s also a tactile benefit I didn’t anticipate: the transition from knob to plate gives a more positive purchase, especially on smaller knobs. It’s subtle, but it makes opening a slick drawer a little easier when your hands are wet or greasy.

Aesthetically, the plates read as “hardware that belongs there.” The satin nickel plays nicely with brushed and satin nickel knobs from a couple of different brands in my shop. The tone is neutral—not too warm, not too cool—so it blended with both contemporary bar pulls nearby and traditional round knobs. On a rehabbed dresser, the effect is almost like a small frame around each knob, which helps unify mismatched drawer fronts.

Where these make sense

• Protecting paint or lacquered finishes in high-touch zones (kitchens, bathrooms, kids’ rooms).
• Masking minor wear, ring marks, or small chips around existing knob holes without a full refinish.
• Adding a subtle design detail to otherwise plain cabinet fronts or furniture pieces.
• Coordinating with satin/brushed nickel knobs when you want a cohesive look across a room.

Because they’re sold as a pack of five, they’re a practical buy for a vanity, a small bank of drawers, or to test a look before committing across a whole kitchen. If you’re doing a larger install, just plan your quantities since most rooms won’t divide neatly into fives.

What could be better

No product is one-size-fits-all, and there are a few constraints to keep in mind:

• Size limitations: At 1 inch wide, these are on the slimmer side. They’re great for subtlety, but if you’re hoping to hide a big patch or mismatched bore, you’ll need a wider plate.
• Screw length: By design, these add thickness. If your existing screws barely catch, you’ll need longer ones. It’s a small thing, but it can stall an otherwise quick install if you’re not prepared.
• Finish matching: Satin nickel varies slightly by brand. These have a clean, neutral satin, but if your knobs lean warm or have a heavy brush pattern, order one pack first and check the match before scaling up.

None of these are dealbreakers; they’re all solvable with a little planning and measurement.

Value and alternatives

In terms of value, these hit a sweet spot: solid build, consistent finish, and a size that elevates without shouting. I’ve used bulk backplates that looked stamped and thin; these feel more substantial and finished. If you need more coverage, you can find larger backplates, but you’ll give up the understated look that works so well here. If your hardware is polished chrome, black, or brass, you’ll want to look for the same style in those finishes or consider mixing metals intentionally.

The bottom line

The Cosmas backplates earned a spot in my standard kit. They solve two common problems—finish wear and visual blandness—without introducing new ones, and they do it with a restrained, well-executed satin nickel finish. Installation is straightforward, the size is thoughtfully compact, and day-to-day they just work.

Recommendation: I recommend these backplates for anyone looking to protect painted or lacquered cabinet surfaces, tidy up minor wear around knob holes, or add a subtle, cohesive detail to cabinets and furniture. Measure your trouble spots to confirm the 2-3/4 by 1 inch footprint will cover what you need, and pick up a few longer screws before you start. If you need to hide more substantial damage or want a bolder design statement, opt for a wider plate; otherwise, these are an easy, reliable upgrade that makes cabinets look finished and keeps them looking that way longer.