Quick Answer

Choose X-21 Flat Base if you want to flatten the finish of your gloss paints or create a matte topcoat. Choose X-28 Park Green if you need a specific olive-green color for military or mecha camouflage. They serve different purposes, so the right pick depends on your painting goal.

When you're shopping for Tamiya enamel colors, you might notice that some paints are named by function and others by color. X-21 Flat Base and X-28 Park Green are a perfect example. One is a tool for adjusting finishes, and the other is a ready-to-use color. Knowing the difference saves you from buying the wrong bottle.

In this comparison, we'll break down what each paint does, how to use them, and the trade-offs you need to consider. We'll also look at a couple of related products from Panda Hobby's catalog to help you make an informed decision.

What Is X-21 Flat Base?

X-21 Flat Base is an additive enamel paint. It's not meant to be used alone as a final color. Instead, you mix it with gloss Tamiya enamels to reduce their shine and create a flat or matte finish. It can also be used as a base to thin other paints, but its primary role is to alter the gloss level of your paint.

For example, if you have a glossy green and you want a subdued, military look, you add a small amount of X-21. The more you add, the flatter the finish becomes. This gives you control over the final sheen without buying a separate flat clear coat.

  • Mix X-21 with gloss enamels in small amounts to avoid a chalky result.
  • Test on a scrap piece first to see how much flattening you get.

What Is X-28 Park Green?

X-28 Park Green is a standard enamel color. It's a dark, muted green that's often used for military vehicles, aircraft, and mecha. It comes ready to use, though you can thin it with enamel thinner for airbrushing or brush painting.

Unlike X-21, X-28 is a final color. You apply it directly to your model. If you want a flat finish, you can either mix in a bit of X-21 or topcoat with a flat clear. If you want a gloss finish, you can leave it as is or add gloss clear.

  • X-28 works well as a base color for camouflage patterns.
  • Use enamel thinner for cleaning brushes and airbrushes.

Key Differences at a Glance

The main difference is purpose. X-21 changes the finish of other paints; X-28 is a color you apply. You can even use them together: mix a drop of X-21 into X-28 to get a flat park green. That's a common trick for matte military finishes.

Another difference is how you measure them. X-21 is used in small quantities, so a bottle lasts a long time. X-28 is used as a main color, so you might go through it faster, especially on larger kits.

  • If you already have a green you like, X-21 can flatten it.
  • If you need a specific green, X-28 is the direct choice.

Trade-offs to Consider

  • X-21 Flat Base: Adds matte finish but can make paint chalky if overused. Requires mixing and testing. Best for painters who want control over sheen.
  • X-28 Park Green: Ready-to-use color but only one shade. You may need to mix it for exact matches. Best for painters who need a specific green quickly.
  • Combining Both: Mixing X-21 into X-28 gives a flat park green, but you must add X-21 sparingly. Ideal for military builds with a matte finish.

Related Products at Panda Hobby

  • X-25 Clear Green (Enamel) 80025: Tamiya Enamel X-25 Clear Green is a clear enamel paint. If you want a glossy green tint over silver or chrome, X-25 can be used as a candy coat. It's a different tool than X-28, which is opaque.
  • XF-19 Sky Grey Mini (Acrylic) 81719: Tamiya Flat Acrylics XF-19 Sky Grey is a flat acrylic paint in a mini jar. If you prefer acrylics over enamels, XF-19 gives you a flat grey that pairs well with X-28 for camouflage schemes, but you'll need to manage different paint types.

Which Should You Choose?

Best for

  • Painters who want to flatten existing gloss enamels without buying new colors.
  • Modelers building military or mecha kits that need a matte finish.

Not for

  • Painters who need a specific green color and don't want to mix—choose X-28 instead.
  • Painters who prefer acrylics over enamels—consider Tamiya acrylics like XF-19 for a flat finish.

In the end, X-21 Flat Base and X-28 Park Green serve different jobs. X-21 is a finish modifier; X-28 is a color. If you're building a military or mecha kit and want a matte green, you might end up using both. Otherwise, pick based on your immediate need: flattening or coloring.