Tamiya 87135 Mark Fit (Strong) Decal Setting Fluid Review (2026)

What Mark Fit Strong is for

Mark Fit Strong is Tamiya's more powerful decal setting solvent, positioned above the brand's standard Mark Fit for decals that resist conforming to a model's surface even after the regular formula. It is meant for situations where a decal needs to settle over raised panel lines, rivets, louvers or tightly curved surfaces like wheel wells or canopy frames, where trapped air or stiff decal film would otherwise leave visible silvering or bridging. Builders working with thicker kit-supplied decals on car, aircraft or armor models, where the decal has to wrap around real surface detail rather than lying on a flat panel, are the main audience for this stronger version.

Bottle and applicator

The product comes in a 40ml bottle with a brush built into the cap, which lets a builder apply the solvent directly to a decal without needing a separate brush. That built-in applicator is convenient for controlled, localized application rather than flooding a whole panel, which matters with a strong solvent since precision limits how much surface area is affected at once. The brush-in-cap design is consistent across Tamiya's Mark Fit line and supports the site's pro that the brush in the cap gives easy, precise application compared to decanting a separate solvent into a dish and using an external brush.

Strength and what it can damage

Because Mark Fit Strong is formulated to soften decal film more aggressively than the standard version, it carries a real risk of damaging thinner aftermarket decals, which are often made with a different film than Tamiya's own kit decals and can wrinkle, tear or dissolve under a strong solvent. Independent sources also note it can affect painted surfaces, particularly acrylic paint, if it contacts bare paint rather than staying limited to the decal itself. This matches the site's con that the strong softener can destroy thin aftermarket decals, and it is worth extending that caution to freshly painted acrylic surfaces near the decal, not just the decal film.

How to use it safely

The standard approach with any strong decal softener is to test it first on a spare decal from the same sheet, since decal film thickness and coating vary between manufacturers and even between sheets, and a formula that works cleanly on Tamiya's own decals may be too aggressive for a different brand. Applying a small amount and letting it work before adding more, rather than soaking a decal heavily up front, gives more control and reduces the chance of the decal breaking apart mid-application. This lines up with the site's own advice to test on a spare decal first to avoid wrinkling before committing to the actual model.

Verdict

For builders dealing with kit decals that refuse to settle over curves, rivets or panel lines even after a standard setting solution, Mark Fit Strong matches the site's score of 8.4 out of 10 as a dedicated tool for exactly that problem, backed by its convenient brush-in-cap applicator. It is not the right first choice for delicate aftermarket decals or for routine flat-surface decal work where a gentler solution would do the job with less risk, and anyone using it for the first time should test on a spare decal before applying it to a finished model.

Frequently asked questions