ᐅ KALLAX Unit Painted Afterwards – Inserts No Longer Fit

A few weeks ago, I painted my KALLAX shelf to better match the color scheme of my living room. The painting itself turned out well, but now the original inserts and shelves no longer fit properly into the compartments. They either stick too much or don’t fit at all, even though I didn’t change the dimensions of the inserts.

My question to the community: Does anyone have experience with how layers of paint affect the exact dimensions of KALLAX units? Should I expect a certain thickness of the paint that reduces the clearance? Are there proven methods to make painted KALLAX inserts fit again without having to glue or saw them? Or is this fundamentally an unavoidable issue once you paint them?

I look forward to your tips and experiences!

Hello Schahin36,

Thank you for your very detailed description of the problem; it makes it much easier to provide help. Regarding the topic "KALLAX painted afterwards and inserts no longer fit," here are a few notes and tips:

1. Layers of paint naturally add up in the millimeter range. For painted wood or MDF, a paint layer can be about 0.2 to 0.5 mm (0.01 to 0.02 inches) thick, depending on the application and the number of layers. For a shelf with very precise insertion dimensions, this can noticeably affect the fit.

2. Especially if you have inserts that fit very tightly (they often match the Kallax standard dimensions exactly), painting the outer surfaces will reduce the internal space, causing the inserts to jam.

3. To solve this problem, you can try the following approaches:

- Lightly sand the insides of the compartments to remove excess paint and create more clearance.
- Also lightly sand the surfaces of the inserts if they were painted and have become too thick.
- Alternatively, slightly modify the inserts (sanding or filing) to better fit the shelf.

4. If this seems too much effort, I recommend taking exact measurements before painting and only painting the outside or areas that do not affect the insertion dimensions.

In conclusion: "While paint provides protection, it also changes the fit of shelves and inserts—therefore, always allow for some added thickness or plan for adjustments."

I hope this helps you!

Nofege schrieb:
The paint does provide protection, but it changes the fit of inlay and insert parts – so always add a bit of material thickness or plan for adjustments.

That sums it up very well. I’d like to add why exactly this happens and how it works technically, because some issues can be avoided.

KALLAX shelves have very precise dimensions. The compartments are often manufactured with tolerances of just a few tenths of a millimeter to ensure inserts fit perfectly. But when you paint, you add layers of between 100 and 500 micrometers (0.1 to 0.5 mm) per surface (front, back, bottom, top, sides). Even just two coats add 0.2 to 1 mm (0.008 to 0.04 inches) of extra material.

Because of the paint thickness, the internal dimensions shrink. This means inserts that previously fit easily may now be tight or no longer fit at all. This problem is common with MDF or particleboard, as these materials absorb paint and become rougher, requiring a thicker layer for adequate protection.

What can you do?

- Before painting, remove inserts and possibly paint only the outer carcass.
- If you do paint everything, measure precisely beforehand and allow a bit of extra space considering the expected paint thickness.
- Afterwards, you can use fine sandpaper to adjust the inner sides and restore the proper dimensions.

Ultimately, this is a balance between design and functionality. For me, it’s important to understand the surface properties and coating thicknesses when customizing such furniture.

I’m curious: What type of paint did you use? Water-based acrylic, spray paint, or wood varnish? Because there are significant differences in layer thickness and flexibility.

Schahin36 schrieb:
Does anyone have experience with how paint layers affect the exact dimensions of KALLAX? Should one expect a certain thickness of the paint that reduces the tolerance?

Yes, the paint layer can definitely cause fitting issues.

Nofege schrieb:
Lightly sanding the inner sides of the compartments to remove excess paint and create more clearance.

That's exactly what I did, and it works well.

Additionally: use thinner inserts or trim the edges slightly if necessary.