# I'd like to make a complex model hollow but with a specified wall thickness **URL:** \ **Category:** Modeling\ **Tags:** modeling\ **Created:** [September 28, 2026, 4:06am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755 "2026-09-28T04:06:18Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Claws\_Cosplay](https://blenderartists.org/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@Claws\_Cosplay](https://blenderartists.org/u/Claws_Cosplay)\ **Post date:** [September 28, 2026, 4:06am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/1 "2026-09-28T04:06:18Z")
I’ve been using Blender for a few years and frequently struggled with this. I have a complex model (a flower with many petals for example). I’d like to print it in resin so infill isn’t a factor. I’d like to print it hollow with a maximum thickness of, for example, 5mm, so that the transluscent resin looks good but I’m not printing giant chunks of solid plastic without a good reason. Adding a hole to let the resin drain is not a problem. I’ve seen the standard answers using Solidify but the when the piece has parts that are thinner than 5mm, each side of a petal will essentially extrude through the other side. I’ve seen the standard answers using Extrude but the same issue applies. I’ve even heard that some slicers can do this but my friends print for me and they aren’t 3D modelers so I’d be happy with advice that included importing to another MacOS app and coming back to Blender. Best case: I can apply a Modifier or tool to an object that has parts thinner than the set thickness and those parts become solid while large volumes gain a thickness of 5mm. ---
**Author:** ![Claws\_Cosplay](https://blenderartists.org/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@Claws\_Cosplay](https://blenderartists.org/u/Claws_Cosplay)\ **Post date:** [September 28, 2026, 5:26am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/2 "2026-09-28T05:26:50Z")
If anyone has a pure Blender solution, I’d still deeply appreciate it. As is always the case, once I ask the question in public, I come up with a limited solution. I downloaded CHITUBOX. Once set up with a theoretical printer that could print my piece, I imported the STL. I selected Hollow. This let me set the wall thickness. Make sure to turn on “Keep the Main Cavity” or it will start putting supports in the middle. Deselect Infill. I selected Drill Holes. This let me create the size hole I wanted and select the depth. Note: If the hole isn’t deep enough to get fully into the central cavity, the hole will “fail to drill” Drill deeper and hit Apply. Export the model and put it back in Blender if you like. ---
**Author:** ![GrimZA](https://blenderartists.org/user_avatar/blenderartists.org/grimza/32/1401336_2.png) [@GrimZA](https://blenderartists.org/u/GrimZA)\ **Post date:** [September 28, 2026, 7:32am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/3 "2026-09-28T07:32:20Z")
Welcome to BA. Do you have a sample we can take a look at? Using solidify is the general approach for hollowing out a model and you’re going to have to do some manual cleanup since no model is the same. But maybe we can work out a better approach? ---
**Author:** ![oo\_1942](https://blenderartists.org/user_avatar/blenderartists.org/oo_1942/32/797904_2.png) [@oo\_1942](https://blenderartists.org/u/oo_1942)\ **Post date:** [September 28, 2026, 12:43pm UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/4 "2026-09-28T12:43:41Z")
![image](https://blenderartists.org/uploads/default/original/4X/3/d/9/3d9eb2d83b6f2be35fa60c9dd588cdea6f02ed10.png) I’m not entirely sure I understand your question correctly. (I am not a native English speaker.) 🤔 I gather the issue concerns the thickness of various independent parts and the process of printing them on a 3D printer. As far as I know, a 3D printer requires a model to be a single, solid mass to print without issues. While the Solidify modifier adds thickness, it does not resolve the problem of objects overlapping or intersecting. Treating the petals as individual objects avoids this issue, but treating them as a single flower shape—which is essentially a collection of separate objects—causes problems due to the intersections. You could resolve this by using a Remesh modifier to merge everything into a single solid mass, but small details often get lost or distorted in the process. ---
**Author:** ![Claws\_Cosplay](https://blenderartists.org/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@Claws\_Cosplay](https://blenderartists.org/u/Claws_Cosplay)\ **Post date:** [September 29, 2026, 3:27am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/5 "2026-09-29T03:27:45Z")
It won’t let a noob to the forums like me upload a file, sadly. Solidify is unsuitable for complex models. Rather than clean up, the entire model is essentially destroyed. The model I started with is linked here. Peony Solid.stl has a large chunk of plastic. The 5mm.stl model is what the slicer spit out after I used it to hollow out the central chamber and drill a hole. > **[Peony Solid.stl](https://drive.google.com/file/d/1ICIJJuREGuQi056aJSXG3ZUb8oJVrzJD/view?usp=sharing)** > > Google Drive file. > **[Peony 5mm Wall.stl](https://drive.google.com/file/d/1oRRoVxg4K_CMCmoK4SmtnO0PKKXEDKP0/view?usp=sharing)** > > Google Drive file. To @oo_1942, thank you but there’s no direct way to separate the pieces. I didn’t make this model but there are similar ones that I have made with the same issue. ---
**Author:** ![Claws\_Cosplay](https://blenderartists.org/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@Claws\_Cosplay](https://blenderartists.org/u/Claws_Cosplay)\ **Post date:** [September 29, 2026, 3:28am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/6 "2026-09-29T03:28:20Z")
I’ve also included what happens to a model if I add a 5mm Solidify Modifier to it: > **[Peony Solidify 5mm.stl](https://drive.google.com/file/d/1FusLfPzWn65L8Ub8IFFa6Fm0J4Ltf5-H/view?usp=sharing)** > > Google Drive file. ---
**Author:** ![oo\_1942](https://blenderartists.org/user_avatar/blenderartists.org/oo_1942/32/797904_2.png) [@oo\_1942](https://blenderartists.org/u/oo_1942)\ **Post date:** [September 29, 2026, 5:35am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/7 "2026-09-29T05:35:24Z")
![image](https://blenderartists.org/uploads/default/original/4X/9/f/d/9fd18d25c1211259f4ee48a33ee1d51a470e793a.png) It appears to be already an object for a printer and there is not enough space to set the thickness. It seems that the Peony 5mm Wall.stl can be printed if the two holes are fixed. ![image](https://blenderartists.org/uploads/default/original/4X/b/d/a/bda8d914bb37b64e4c5ed8db2301dcfc49480e14.png) And you need to fix the hidden issues. ---
**Author:** ![Claws\_Cosplay](https://blenderartists.org/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@Claws\_Cosplay](https://blenderartists.org/u/Claws_Cosplay)\ **Post date:** [September 30, 2026, 5:49am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/8 "2026-09-30T05:49:58Z")
The 5mm one prints fine but that’s after the slicer made it hollow. My question stands: Is there a way to perform something similar in Blender starting from the Solid.stl? Is there a way in Blender to leave the outside alone but hollow out the inside to a specific thickness? ---
**Author:** ![oo\_1942](https://blenderartists.org/user_avatar/blenderartists.org/oo_1942/32/797904_2.png) [@oo\_1942](https://blenderartists.org/u/oo_1942)\ **Post date:** [September 30, 2026, 11:47am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/9 "2026-09-30T11:47:52Z")
![image](https://blenderartists.org/uploads/default/original/4X/9/6/0/960a1c24db18f726d7e5047c2cdda573204d7fc7.png) The messy topology of Peony Solid.stl causes problems when using the Solidify modifier. You can consider using the Sculpting tool to tidy things up. It is uncertain whether the desired thickness can be achieved with the Solidify modifier. How much space you create depends on how you organize the topology using the Sculpting function. I am not sure about the other methods. Geometry nodes can provide more control, but it is unclear whether this will be resolved. ---
**Author:** ![Claws\_Cosplay](https://blenderartists.org/letter_avatar_proxy/v4/letter/c/d9b06d/32.png) [@Claws\_Cosplay](https://blenderartists.org/u/Claws_Cosplay)\ **Post date:** [October 1, 2026, 7:26am UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/10 "2026-10-01T07:26:10Z")
The Peony is one example. I’ve used very clean models that I’ve built from scratch and had this issue. The Peony is just the one I had at hand when it came up again. As far as I know, there’s no way in Blender to extend the outer edges of a model into itself in such a way that merges the newly created inner surfaces. Solidify is never the right solution unless you have an extremely simple surface with no overlapping parts that’s already just one side. It’s not appropriate for a manifold object of any complexity. ---
**Author:** ![oo\_1942](https://blenderartists.org/user_avatar/blenderartists.org/oo_1942/32/797904_2.png) [@oo\_1942](https://blenderartists.org/u/oo_1942)\ **Post date:** [October 1, 2026, 1:40pm UTC](https://blenderartists.org/t/id-like-to-make-a-complex-model-hollow-but-with-a-specified-wall-thickness/1653755/11 "2026-10-01T13:40:58Z")
![image](https://blenderartists.org/uploads/default/original/4X/b/7/5/b75143c0b45c71cbfcd151b70c520c1e37503083.png) ![image](https://blenderartists.org/uploads/default/original/4X/5/b/2/5b246cbe6f3a0d6e8852384a31958aeb08e1075d.png) It’s not completely impossible; it can be resolved to a reasonable extent. However, the results may not meet your desired level, and there may be unresolved defects; you will need to address these issues yourself. The results vary depending on the modeling state.