# Mask and shell

**URL:** https://forum.nomadsculpt.com/t/mask-and-shell/6107
**Category:** Lounge
**Created:** [March 6, 2022, 2:43pm UTC](https://forum.nomadsculpt.com/t/mask-and-shell/6107 "2022-03-06T14:43:25Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![Terrods](https://dub1.discourse-cdn.com/flex005/user_avatar/forum.nomadsculpt.com/terrods/32/8627_2.png) [@Terrods](https://forum.nomadsculpt.com/u/Terrods)
#### Post date: [March 6, 2022, 2:43pm UTC](https://forum.nomadsculpt.com/t/mask-and-shell/6107/1 "2022-03-06T14:43:26Z")

</div>

![image](https://europe1.discourse-cdn.com/flex005/uploads/nomadsculpt/original/2X/3/345a8882bc001530a3fbd40400f7f8361fe6264f.jpeg)  
 ![image](https://europe1.discourse-cdn.com/flex005/uploads/nomadsculpt/original/2X/e/ed9ef563227c7e301be657967c41b06f3db31201.jpeg)  
 ![image](https://europe1.discourse-cdn.com/flex005/uploads/nomadsculpt/original/2X/9/96990dc9c7d6aa76ea82122553814cb5b2467d1f.jpeg)

So I have been playing around with mask → extract shell to create printable negative moulds. However it tends to cut back into itself ruining the surface of the mould. I have tried to then use a copy of the original piece as a hollow and then voxel merge it with the shell, but that kind of messes up the surface as well, for some reason. Any tips to work around this?

---

<div class="post-metadata">

### Author: ![RogerRoger](https://avatars.discourse-cdn.com/v4/letter/r/b2d939/32.png) [@RogerRoger](https://forum.nomadsculpt.com/u/RogerRoger)
#### Post date: [March 6, 2022, 3:54pm UTC](https://forum.nomadsculpt.com/t/mask-and-shell/6107/2 "2022-03-06T15:54:39Z")

</div>

Why are you trying to make a shell?  
Why not make a cube around the sculpt, then subtract the sculpt out of the cube? Then you have your negative.

 ![image](https://europe1.discourse-cdn.com/flex005/uploads/nomadsculpt/original/2X/8/870fb651c8848cb9da97cdf2330e1f63f0f2debb.jpeg)

 ![image](https://europe1.discourse-cdn.com/flex005/uploads/nomadsculpt/original/2X/e/e6b9bed79d567a2b44dd828c69e4770e433395ae.jpeg)

---

<div class="post-metadata">

### Author: ![Terrods](https://dub1.discourse-cdn.com/flex005/user_avatar/forum.nomadsculpt.com/terrods/32/8627_2.png) [@Terrods](https://forum.nomadsculpt.com/u/Terrods)
#### Post date: [March 6, 2022, 4:11pm UTC](https://forum.nomadsculpt.com/t/mask-and-shell/6107/3 "2022-03-06T16:11:24Z")

</div>

I have done this as well but a shell would really allow me to do larger more cost (and time) effective prints

---

<div class="post-metadata">

### Author: ![Holger\_Schoenischka](https://dub1.discourse-cdn.com/flex005/user_avatar/forum.nomadsculpt.com/holger_schoenischka/32/3934_2.png) [@Holger\_Schoenischka](https://forum.nomadsculpt.com/u/Holger_Schoenischka)
#### Post date: [March 6, 2022, 4:32pm UTC](https://forum.nomadsculpt.com/t/mask-and-shell/6107/4 "2022-03-06T16:32:58Z")

</div>

> [@Terrods](#):
>
> messes up the surface

Try a thinner extraction - the shell seems to cross in some places. Make a SelMask through the affected areas and then hide the mask. Then check the mesh.

 ![image](https://europe1.discourse-cdn.com/flex005/uploads/nomadsculpt/original/2X/0/0292cfe1c45474169b49261195b0721d816101db.jpeg)