Solid vs. Hollow: When to Hollow Your 3D Prints
A Guide to Saving Resin & Why Large Solid Models Are a Trap
You’ve just downloaded a massive dragon. It’s the centerpiece for your next campaign. You open your slicer, and you’re faced with the first big question: “Should I print this solid or hollow?”
The answer isn’t a “maybe” or a “spectrum.” Instead, there is a clear, correct choice, and making the wrong one will lead to a costly, toxic disaster.
As experts who test-print thousands of models, we’re here to give you the golden rule, save you a ton of resin, and help you avoid the number one trap that new printers fall into.
The Golden Rule: Solid for Small, Hollow for Large
This is the only rule you need to remember.
Small Miniatures (e.g., 28-32mm heroes) SHOULD be Solid. For a standard, human-sized miniature, the resin savings from hollowing are almost zero. In fact, attempting to hollow a model that small makes it fragile and can cause the print to fail. For 32mm minis, “solid” is therefore the best choice for maximum durability.
Large Models (e.g., Monsters, Busts, 75mm+ models) MUST be Hollow. This is not a suggestion; conversely, it’s a requirement for a successful, safe print. Ultimately, printing a large model solid is the single most common reason for catastrophic print failures, even weeks after the print is “finished.”
The “Solid Print Trap”: Why You Should NEVER Print Large Models Solid
“But,” you might ask, “won’t a solid print be heavier and sturdier?”
This is the most dangerous myth in 3D printing. In reality, a large “solid” model is not solid. It is a cured outer shell filled with a core of liquid, toxic, uncured resin.
The UV light from your printer cannot penetrate more than a few millimeters, so the entire inside of the model remains raw resin. Consequently, this makes your “solid” print a resin time bomb. Over time, one of two things will happen:
It Will Leak: The uncured resin will find a micro-crack (or create one) and ooze out, covering your shelf or gaming area with toxic resin.
It Will Crack Itself Apart: The uncured resin inside continues to off-gas, building up internal pressure until it cracks your beautifully painted model from the inside out.
Heft should come from a properly cured, thick-walled hollow model, not a liquid-filled trap.
The Guide to Hollowing: The Benefits and “The Hard Part”
Hollowing is the only professional, safe, and economical way to print large models.
Benefit 1: Massive Resin Savings. The benefits are obvious. For instance, as we showed in our guide to scaling, properly hollowing a model can reduce resin usage by almost 50%.
Benefit 2: Safety & Success. It’s the only way to ensure you cure the entire model and make it chemically stable.
“The Hard Part” (The Cons): However, be honest. To do this right, you must do two things:
1) Internal Supports to stop the cavity from failing.
2) Drainage Holes strategically placed to let resin and air escape.
The Loot Studios Solution: We Do “The Hard Part” For You
That whole “hard part” we just described? That complex, frustrating job of hollowing, adding internal supports, and testing drain hole placement?
We do it for you.
Our team of 3D printing experts has already done this tedious job on every large model we release. In fact, every hollowed Loot file you download comes:
- Perfectly hollowed to a 2mm wall thickness.
- Internally supported to prevent any failures.
- Optimized with drain holes for a clean, successful print.
We don’t just sell you an STL file; instead, we provide a fully-tested, expert-engineered solution so you can skip the frustration and get right to the perfect print.
Which Loot File Should I Choose?
Now, that file list on our website makes perfect sense. Here’s how to choose:
| File Name | Description |
| Solid | Use this for 32mm heroes and small minis. They are designed to be solid for maximum durability and easy printing. |
| Hollow | Use this for all large models (monsters, busts, 75mm). It’s pre-optimized by our experts to save you resin and guarantee a safe, successful print. |
| Unsupported | For advanced users only. This file is for those who wish to do the hollowing, scaling, and support process themselves. |
Final Thoughts
Now that you understand why hollowing is so important, you can print with confidence, knowing you’re not just saving resin, but you’re also printing a safe, stable model that will last a lifetime.
Are you confident about what resin to use for that model? If not, check our full guide on that matter.
Loot Studios can help you paint highly detailed minis, statues, and props. Choose your favorite bundle from our previous releases or sign up for Fantasy or Sci-Fi to receive a new bundle every month. You can also check out some tips on our YouTube Channel.
