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How the Sulfur Cube's texture works, and how to paint one

Minecraft 26.x added the Sulfur Cube, a slime-family mob built around swallowing blocks and changing behavior. We opened the real client jar to see exactly what a resource pack can and can't change about it — here is what's actually inside, and a practical workflow for repainting it.

Open the texture painter

What's actually in the resource pack

A Sulfur Cube ships four PNG files, all under assets/minecraft/textures/entity/sulfur_cube/:

FileSizeUsed for
sulfur_cube_outer.png128×128Full-size cube's visible shell and face
sulfur_cube_inner.png128×128Full-size cube's inner layer
sulfur_cube_outer_small.png64×64Small cube's visible shell and face
sulfur_cube_inner_small.png64×64Small cube's inner layer

The small/full-size split mirrors the classic Slime pattern: the jar also defines a separate SmallSulfurCubeModel, which is almost certainly the model used after a Sulfur Cube splits, the same way a Slime splits into smaller Slimes on death.

Why you can't reshape it

The cube's actual geometry lives in compiled Java classes (SulfurCubeModel, SmallSulfurCubeModel, SulfurCubeRenderer), not in a JSON entity model you can edit. This is normal for vanilla mobs — unlike items and blocks, mob geometry generally isn't resource-pack-editable. A resource pack can replace the four PNGs above, and nothing else about the mob's shape.

Two layers, two jobs

The two texture names aren't decorative. The jar defines a dedicated SulfurCubeInnerLayer render layer, separate from the base model, which is why there are two independent textures instead of one:

Practically: if you only touch sulfur_cube_outer.png, you're repainting what players actually see most of the time. The inner texture is worth customizing too, but treat it as an abstract pattern, not a face or a body part.

The swallow mechanic doesn't get its own texture

The Sulfur Cube can swallow certain blocks and items (there are sulfur_cube_swallowable and sulfur_cube_food tags defining what), and the jar defines twelve distinct behavior archetypes — bouncy, explosive, fast_flat, fast_sliding, high_resistance, hot, light, regular, slow_bouncy, slow_flat, slow_sliding, and sticky — plus a SulfurCubeContent item component that almost certainly records what a given cube swallowed.

What we did not find is twelve sets of textures. There's exactly one outer/inner pair for the full-size cube and one for the small one, regardless of archetype. That strongly suggests archetype and swallowed content change behavior and possibly an in-game color tint, not which texture file gets loaded. We're stating this as an inference from the file list, not a confirmed fact about the renderer — but the practical takeaway is solid either way: a custom resource pack skin applies to every archetype equally. You cannot give the "hot" cube a different look from the "sticky" one through textures alone.

Painting the outer skin

  1. Open the texture painter and set the canvas size to 128×128 for the full-size cube, or 64×64 if you're painting the small variant.
  2. There's no built-in Sulfur Cube template, so you're painting on a blank canvas at the right resolution — the same way you'd approach any vanilla mob retexture. Block in the base color first, keep the front face's eyes and mouth simple and high-contrast (they're what players actually focus on), and add surface detail last.
  3. Zoom back to real size often. At this resolution, a cube seen from a few blocks away reads mostly as color and silhouette — the same rule from our texture size guide applies here.
  4. Export as sulfur_cube_outer.png (or sulfur_cube_outer_small.png).

Painting the inner layer

For the inner texture, don't reach for a face template — paint an organic, blotchy pattern instead: clumped color regions with soft edges, similar to a marbled gas cloud. Since it's most visible through gaps or translucent spots in the outer shell, high local contrast in a few small areas will read better than a texture that's busy everywhere.

Packaging the pack

The resource-pack generator is built around items, blocks, armor, and CustomModelData slots, and doesn't currently expose raw entity texture paths like this one. For a mob retexture, build the folder structure by hand instead: a pack.mcmeta at the root, matching the standard resource pack path layout, with your PNGs placed at exactly assets/minecraft/textures/entity/sulfur_cube/<filename>.png, then zip the folder (not a folder containing the folder) for a working resource pack.

FAQ

Can I make the Sulfur Cube a different shape with a resource pack?

No. Its geometry is compiled into the game's Java code, not defined in an editable JSON model. A resource pack can only replace the four texture files — it can't add limbs, resize the cube, or change its silhouette.

Do I need to edit all four texture files?

No. If you only care about the full-size cube's normal appearance, sulfur_cube_outer.png alone covers what players notice most. Skip a file and the game keeps using the vanilla version of it.

Will my custom texture look different depending on the archetype (bouncy, hot, sticky, etc.)?

Almost certainly not through the texture itself — there's only one texture pair regardless of archetype. Any visual difference between archetypes, if there is one, would come from an in-game tint applied on top of your texture, not from the pack.

What happens if I get the pixel dimensions wrong?

Minecraft will still try to load a mismatched PNG, but the UV mapping baked into the model expects exactly 128×128 (or 64×64 for the small variant), so anything else will stretch or misalign badly. Keep the canvas size in the texture painter matched to the file you're replacing.

Where to go next

New to painting mob skins in general? Start with our texture size and workflow guide for how to think about silhouette, contrast, and tiling before you commit to a final design.