Greedo - Best way to go from Zbrush sculpt to silicone mask?

[Rubber Slug]

(Screenshots in Unreal Engine 5)

I've never attempted to make a silicone mask before, but my love of Greedo has forced me into this project. Right now I have a zbrush sculpt that I'm more or less happy with, and I can 3D print this sculpt at 1:1 (although I might have to do it in pieces). However, I want to go all the way and turn this into a mask. That said, it seems like there are a ton of different methods to accomplish that goal. I'd like to get it done as cheaply as possible, and with as little frustration as possible.

• Is it a bad idea to 3d print a multi-part hard mold and slush cast silicone directly into that?
• What about a brush-on mold?
• Something else entirely?
• Do I need to mold the ears and antennae as separate pieces to avoid undercuts?

Thanks!

 

[animator]

Looks like a great project!
I don't have experience with this personally, but I would look into printing a mold and core. Having a core should give you better results than trying to slush cast silicone. You could even plan in some mouth and antenna controls with the core design.
I have wanted to try this sort of project, but still need to learn Zbrush.
Casting silicone in a mold with a core is actually really easy and fun.
Hopefully you will get some experienced advice. Please post your progress!

 

[Rubber Slug]

Thanks for the idea! Do you mean something like this?

By the way, I learned Zbrush from Michael Pavlovich's YouTube videos. If you want to learn Zbrush starting from nothing, I don't think there's a better teacher.

 

[animator]

That is a good video from Smooth-On. Smooth-On also has a help line which is fantastic for getting advice and options.

Another good source of information would be the Stan Winston online school's videos "Silicone Mask Making Part 1-3". They have a number of videos including patching and painting silicone which would be worth watching if you don't have experience with this.

If you can design the mold and core digitally using Booleans of the sculpture, you could potentially get fantastic registration and accuracy without the need to learn all the steps and products that go into creating a mold and core from a practical sculpture. Again, I haven't done this and don't know how to go about printing a clean enough mold, but I think some people are doing this. It's on my list to try someday.

In terms of the core, here is the mold and core to my dragon puppet. You can see the core fills most of the void of the mold.

This shows the holes at the base. I pour silicone in one hole and the others allow air to escape. (I cast it with the base at the top). Doing it this way means I don't need to waste any silicone and I only have to worry about patching the mold seem line which is minor.

Thanks, I'll check out those Zbrush videos.

Good luck with the project! There are super talented and experience professionals on this forum who will hopefully jump in with better advice. It's just a hobby for me which explains why my mold and core are so sloppy.

 

[animator]

Any progress on your project?

 

[Rubber Slug]

Sort of. It's been a lot of work with booleans trying to get clean geometry for the mold, but I'm getting there. I think it's just a matter of figuring out the best software for the workflow.

If it doesn't work out, I'm gonna have to mold and cast the old fashioned way. I'll post an update once I make progress on the 3D printed mold.

I'm also thinking about how I could possibly get Greedo's antennae to move around like they do when he's played by Maria De Aragon. I want to try to avoid servos because of how sweaty it will be inside the mask, not to mention the extra complication of adding a battery and wiring. If anyone has an idea of how to do it with cables, I'm all ears.

 

[udog]

The first thing to do in your case would be to make the core. Without it the result will be very random. The core is necessary to get a nice snuggy fit.
I do these kind of things 100% hand made, old school, so I can´t tell say much about making it with Zbrush.
The old school route would be first making the core, sculpting on it and then molding. This way everything will be in place with the desired thickness if done correctly, which is not that easy actually.
In your case if you 3d print it will probably be easier to design and print everything, character, core and mold. Sounds easier. If you try to combine both techniques you might have to make several molds and castings that would work as a transition to achieve the final mold and core. Sounds a bit ball breaking and probably expensive.

As for a way of moving the antennae with cables, not sure what kind of movement you´re after. But nice organic motions can be achieved with cable and rubber tubes or similar. Get a flexible rubber tube, make wedge/angle shaped cuts where you want it to bend, Then you fix the cable tip to one of the rubber tube tips (the cable runs inside the tube) and pull. It will bend where you made the cuts. Of course you´ll have to figure out what is the best way to run the cables through the head etc. Sounds fun.
Or maybe the silicone will act as the tube would and you can just use cables in it and pull, it will wiggle as a worm.
It´s an ole one, but it might give you some ideas. There must be videos with similar stuff out there in the internet. It´s a matter of thinking it out and testing.
Actually, if you were using servos you would have to figure out similar systems. At the end a servo is just substituting the hand that pulls in most cases.

 

[Rubber Slug]

Thank you for all the excellent advice! I was actually thinking the best way to achieve the motion might be to have a servo and controller hidden on my back somewhere and a cable or two running up the back of the mask. Like you said, I need to think it through and try things out. I'll keep this thread updated as I make progress.

 

[Mottrex]

If you want to use cables then your going to need some form be it 3D printed or harness to keep the cables where you want them, if you imagine like a rigid skull cap to mount them to stop movement. I guess it depends on how soft/flexible the mask will be but any loose cables could end up puckering the mask. Actually I had a thought.. If you used those key rings that come with a retractable cord and mounted them inside the ears it Cound give an interesting movement ?

 

[Rubber Slug]

I think you're right about mounting the cables to some kind of harness. I wonder if using a stiffer silicone would be adequate.

Anyway, I finally made progress with the mold design:

 

[drusselmeyer]

Dragonskin 30 will probably be your best bet for casting. It is stiffer, but it remains very flexible.

 

[animator]

Check to see if there is a Reynolds Advanced Materials store near you to visit. They sell everything Smooth-On and will have fantastic advice and silicone samples so you can see how dense/flexible they are. If you can't get to a Reynolds store, Smooth-On has a help line. They have saved me from tons of mistakes. I mentioned their help line before, but I can't stress how helpful they have been to me. There really understand the products!

The thin frills on Greedo's head will likely need bleeder holes in the mold so you can get silicone in there. Once some silicone bleeds out you just cap the holes with clay. Otherwise, you may want to fill those with silicone prior to closing the mold, let that partially set (10-20 minutes) and then cast the rest.

Just a thought, if you are wanting to animated things like antennae and possibly snout (which would be perfect), you may want some sort of thin, stiffer under skull or cap to mount the mechanisms and localize the motion. Maybe like a thin foam cap you could cast, or a fiberglass cap. The puppets I make have foam or fiberglass parts to take the place of skull and jaw bones and hold the volumes. This lets me use softer silicone for better movement and keep the silicone skin thinner. Silicone gets heavy!

If you don't use an under skull, Dragon Skin 30 might be just right.

Trial sets of different silicones are pretty cheap and worth testing a few. I started casting in Dragon Skin 20 and 30. It's fantastic and tough, but too stiff for my uses. I ended up mostly casting with Ecoflex 00-30. If something needs to be more structured or durable, I use Dragon Skin 10. If I want something really flexible, I use Ecoflex 00-20. Ecoflex 00-30 has a really long pot life which gives me plenty of time for degassing and pouring the silicone. Since I'm just a hobbyist, I am very slow at this stuff and appreciate long working times.

Good luck!

 

[Rubber Slug]

Thanks for all the advice! I was waiting on some cured samples Smooth-On said they'd mail to me two weeks ago, but they never arrived. I think I'm going to buy a couple sample kits of Dragon Skin 20 since I found it on Amazon with free shipping. Two sample kits should be a bit more silicone than I need, assuming my math is right.

For the mohawk frills, I was actually going to pour it as a separate mold, then use Sil-Poxy to adhere it to the mask when they're both fresh out of the molds. Might turn out to be a bad idea, but we'll see.

Right now I'm getting all the parts of the mold ready for printing in Siraya Tech Blu for strength, but it also has the advantage of being transparent which should make casting pretty cool.

 

[animator]

Sounds like a good plan! I just checked the Smooth-On site, and their shipping costs are not good.

Can I ask how you are printing the mold? I'm really excited to see your results!

I watched the videos you suggested and am now sort of able to use ZBrush. My next project will hopefully be an animatronic using some of these same steps.

 

[Rubber Slug]

I'm going to be printing it on my Peopoly Phenom L printer with Siraya Tech Blu. I'm also going to try heating the vat with a fermentation belt since Blu needs a higher printing temperature to get the best results. I've never printed anything as big as these pieces, so I'm a little nervous about them falling off the build plate due to their weight. One nice thing about printing a negative mold is that I can place almost all the supports on the outside surface where they won't impact the final surface detail of castings at all.

I'll be printing the core of the mold on my CR10 to save a little money since it doesn't need to be as detailed. That should be relatively straightforward compared to the resin printing (knock on wood).

 

[udog]

Dragon Skin 20

If I understood well, this is a wearable mask?
Silicone mas must be stretchy enough to put it on in first instance (head musty go through the neck, obviously), but also if you expect facial movement of some kind it must be soft enough to copy the wearers mimics.
That´s why Ecoflex 0030 is the standard for mask making among other reasons like it´s long pot life. Not saying it´s what you need but most silicone masks you see online are Ecoflex. The ones I´ve made too.
Sometimes you could combine it with stiffer silicones in areas you don´t want to move so much or other reasons (teeth for example), but that´s trial and error mostly.
So in my opinion DGSK 20 is far too stiff for a mask.
All this said if I understood well.

Sil-Poxy to adhere it to the mask when they're both fresh out of the molds. Might turn out to be a bad idea, but we'll see.

Once cured adhesion is compromised with silicone, not that easy. You´ll have to clean it very well with IPA for example before, and I suggest brush heptane on the area right before glueing. It makes the silicone swell for a moment (goes back to it´s place) and this aids adhesion. Also using a hair dryer to keep the area warm during the process helps.

 

[animator]

So in my opinion DGSK 20 is far too stiff for a mask.
All this said if I understood well.

I would agree with udog! Ecoflex is a better bet. Much thinner and easier to cast as well. Udog always has great advice and a lot more experience than I do.

Once cured adhesion is compromised with silicone, not that easy. You´ll have to clean it very well with IPA for example before, and I suggest brush heptane on the area right before glueing. It makes the silicone swell for a moment (goes back to it´s place) and this aids adhesion. Also using a hair dryer to keep the area warm during the process helps.

What I have usually done is within 12-15 hours of casting, use thickened silicone to bond parts together, like you would in patching flaws. This has worked relatively well for me.

Try not to be disappointed if it takes you a number of tries to get something you like. I went through testing different silicones and bad casts. All a very interesting learning process.

I often use Dragon Skin 10, 20, 30 for molding things I will cast in resin or foam. I use Eco-flex 00-50, 00-30, 00-20 for casting anything I want to move like skin. For example, I used Ecoflex 00-50 for the dragon's ears because they are a longer span with no internal structure and I wanted the ears a bit stiffer like cartilage, but the main skin is Ecoflex 00-30.

I love Ecoflex 00-30!

Lastly, maybe look into making a power mesh hood to put over the core and embed in the silicone when you cast. It's easy to do and really adds some strength.

 

[Rubber Slug]

If I understood well, this is a wearable mask?
Silicone mas must be stretchy enough to put it on in first instance (head musty go through the neck, obviously), but also if you expect facial movement of some kind it must be soft enough to copy the wearers mimics.
That´s why Ecoflex 0030 is the standard for mask making among other reasons like it´s long pot life. Not saying it´s what you need but most silicone masks you see online are Ecoflex. The ones I´ve made too.
Sometimes you could combine it with stiffer silicones in areas you don´t want to move so much or other reasons (teeth for example), but that´s trial and error mostly.
So in my opinion DGSK 20 is far too stiff for a mask.
All this said if I understood well.

It's gonna be wearable, but a bit different from other silicone masks in that the mask's movement isn't coming directly from my facial movements, but from a servo or some other mechanism since it won't be skin-tight all the way around my head. I was also planning to cut a slit in the back to assist in putting it on like they did in the movie (although maybe not so long of a slit). My idea with using a stiffer silicone is to reduce drooping. I think you guys might be right about 20A being too hard, though.

Once cured adhesion is compromised with silicone, not that easy. You´ll have to clean it very well with IPA for example before, and I suggest brush heptane on the area right before glueing. It makes the silicone swell for a moment (goes back to it´s place) and this aids adhesion. Also using a hair dryer to keep the area warm during the process helps.

Thanks for the tips, do you think it's worth redesigning the mold to do the whole thing as one pull? Or do you think the idea of gluing on the mohawk afterwards could work as long as I do it the right way?

I often use Dragon Skin 10, 20, 30 for molding things I will cast in resin or foam. I use Eco-flex 00-50, 00-30, 00-20 for casting anything I want to move like skin. For example, I used Ecoflex 00-50 for the dragon's ears because they are a longer span with no internal structure and I wanted the ears a bit stiffer like cartilage, but the main skin is Ecoflex 00-30.

I love Ecoflex 00-30!

Thanks for the advice again! I guess I should have said before that my goal isn't to achieve a realistic skin, but to make a mask that looks and moves like the original Greedo mask. For example, I intend to make it completely opaque like painted latex, even though that's a waste of silicone's translucency.

Lastly, maybe look into making a power mesh hood to put over the core and embed in the silicone when you cast. It's easy to do and really adds some strength.

I had been considering it, but I got a little worried when I read about other people having issues with the powermesh trapping air bubbles during casting. The added strength of Dragon Skin 20/30 (and cutting a slit in the back) was what made me think I could hopefully avoid that whole step.

Please tell me if you guys think I'm making a big mistake here! I'm definitely open to doing it differently from my current plan, just want to make sure I'm giving you all the info.

 

[animator]

Thank you for the additional explanation! It is very important to view any advice through the lens of your personal goal. What you want to achieve is all that matters!

I feel like I am hijacking your thread which I don't mean to. Please feel free to completely ignore my advice. I honestly am just trying to let you know what I wish someone had told me. Please udog, Mr Mold Maker, or anyone else correct me on any of this! It helps me learn!

Cast in parts/single cast -I would go with a single cast for the entire mask, but start by small tests. Print a small test mold of an area only having one antenna and maybe 8 frills plus 3 or 4 inches of connecting skin. Add a small bleeder hole for the antenna. Mix a small batch of silicone, color it, use a syringe to fill the frills and antenna, then use a toothpick to release any air in the frills or antenna. let that gel 15/ 20 then do another small batch of silicone and fill the connecting skin. This would replicate the steps for a real casting and let you know about possible problems. This can make sure the frills and antenna cast well and release without tearing. you could also use this mold to test coloring and different silicones. cast one with power mesh on the back and see the difference. Test one completely opaque and one making use of deeper colors and translucency, pick the one you like! I really wish I had started with smaller mold tests. I literally spent thousands of dollars to learn what I could have with under $100.

Dragon Skin/ Ecoflex - I vote 100% Ecoflex. If I was casting this, I would try Ecoflex 00-50 for the frills, antenna, and some of the larger bumps, then pour the main skin in Ecoflex 00-30 with a power mesh backing. Possibly even Ecoflex 00-20. Degass the silicone! I bought a small cheap degassing chamber on Amazon that works fine.

slit up back -this is completely your call in terms of style or accuracy to original. I would not, personally add a slit in the back. If you do, absolutely use power mesh! Once silicone is cut or starts to tear, power mesh is the only thing I know that will stop the tearing. If I put a cut in Dragon Skin 30, I can easily tear more from that point. I have not had issues casting with power mesh, but that is just me. I buy power mesh through Reynolds. If you cast in Dragon Skin, I think you will definitely need a slit up the back to be able to pull the mask on.

Seeing my advice, I am going to try test printing a small mold from my ZBrush model and test casting.

Please post pictures of the molds you print!

 

[Rubber Slug]

You convinced me I should definitely start with smaller scale tests rather than jumping right into the full mold and possibly wasting a bunch of money. I printed a little box mold in PLA since the surface finish won't matter for this test (except for the potential for a mechanical lock I suppose).

I think I might have some trouble getting it out of the mold, but we'll see.

I ordered this vacuum chamber and a trial unit of Ecoflex 00-50 from Amazon, which should arrive on Sunday.