Compared
The base coat is about adhesion and staining: it gives the colour something to grip and keeps a dark pigment off the nail plate. The top coat is about abrasion and shine: it takes the wear so the colour does not. If you only ever buy one, buy the top coat, because chipping is what ends most manicures — but a manicure that lifts in two days is the base coat talking, and no top coat will save it.
OPI
Anyone whose polish lifts within days, and anyone wearing a dark shade
Pros
Cons
OPI
Anyone whose polish chips at the tips within a day or two
Pros
Cons
| OPI | OPI | |
|---|---|---|
| Goes | Under the colour. | Over the colour. |
| Problem it solves | Lifting and staining. | Chipping and dullness. |
| If you skip it | Polish peels off in sheets. | Tips wear away first. |
| Visible? | No. | Yes — the shine is it. |
| Can be added later | No. | Yes, over a worn manicure. |
| Buy this one first if | It comes off whole, early. | It wears away at the edges. |
Everything above is about what these products are, not about tests we ran — we do not test products, and we would rather say so than imply otherwise. Prices live on Amazon, where they change hourly, so we never quote one.
Look at how it fails. Polish that peels away in one piece, taking the whole nail's worth with it, is an adhesion problem and that is the base coat. Polish that wears back from the free edge and goes dull is an abrasion problem and that is the top coat. The failure names the missing step.
Combined base-and-top formulas exist and are a compromise by construction: adhesion wants to grip the nail, abrasion resistance wants to be hard on the outside. Two thin bottles do more than one thick one.
Your turn
An occasion you cannot find anything for, or a product you want us to look at properly.