Wigs The right kind of liquid latex?

I can help with some of this.

Let's start with types.
Latex is a natural material and the emulsion used for liquid latex is at it's core very similar between brands. The type sold for moldmaking is usially sold in bigger bottles and therefore tend to be a lot cheaper than the stuff sold for special effects, but I know several people personally who do special effects and they tend to use the same stuff for both.
The one thing that may differ is that sometimes the stuff sold for make up is allready tinted to resemble skin, while the moldmaking stuff is usually not.
There may be a difference in viscosity between brands and some may have a record of ageing differently, but more in that later. In essence, it's all the same stuff.

The colour:
Latex will always get that amber colour. The way I undestand it, what we see is actually oxidization, much like when the polyurethane of our dolls yellow with age. It can't be avoided, it happens upon contact with oxygen.
The latex is fairly transparent and in thin layers the colour won't show up much. It's when you start to build a bit of thickness that it becomes visible. It also darkens a little bit over time.
It is possible to tint latex. latex based hobby paints work fairly well for this and so does other types of acrylic paint, but be aware that there are often things in the paint that speeds up the breaking down of the latex, shortening it's lifespan.

Witch brings us to ageing.
This is the main reason that latex is not a very popular crafting material in any broad sense. It's mostly used for temporary things, like molds for casting a lasting copy of a thing, or for makeup effects that will be washed off at the end of the night, of special effects that is ment to last for a season or two, or for as long as it takes to shoot a movie.
When latex dries out it shinks and becomes hard and brittle.
When it breakes down because of chemical interference (the main problem is grease, but ther are other things that can cause this as well, I don't know enough to give any detailed chemistry lessons, but anything mixed in or stored in contact with the latex can potentially cause this.) it becomes sticky and eventually dissolves into goo.

Just to give an example of how this is handeled: Latex masks are often used along with grease paint, so for storage it's adviced to thuroughly clean the mask with soap and water, dry it carefully, then cover the surface in talcum powder and store the mask in an air tight container in a dark place. And, of course, common beginner mistakes include thing like using a hand soap with moisturizer or talcum with lanolin in it. Even when everything is done right, the mask is not expected to last forever and the mold is usually kept to remake the mask as neccesary.
Heat, light and high humidity speeds the ageing up further.
The ageing starts allready in the bottle, so only buy from reputable places who actually know how to store the stuff and when to get rid of an old product.
The age of the latex will change how it behaves, so don't be too surprised to read conflicting revievs on the same product or have the same brand behave differently from purchase to purchase. This is pretty normal and you learn to work around it.

Latex is amazing, when new, but it does age unperdictably and often quite badly.
If you are lucky you may get a good ten years out of your wig, but eventuall it will break down one way or another.

Ever seen those pictures where someone have used a baloon as a temporary friction cap under wigs and forgetting about them? Guess what regular party baloons are made of?

 

I know nothing about latex so I can't help you with that but I do know a bit about silicone! Theres the art grade silicone that is indeed 2-part, some are brushable, some perfectly see-through, you can tint it etc. But of course you'll also need to use it up quickly after mixing the parts together so it's only great if you want to make a ton of wig caps in advance. You can find tons of different options made by Smooth-On.

There is also, indeed, silicone and acrylic caulk that can be used with a little bit more effort and you don't have to worry about using up a lot in one go. Here's a good wig-cap tutorial using it. Check the product before you use it, though - some of them can irritate the skin and smell quite strong so be careful.

The only worry with those materials is that when they rip there is no fixing it so it's good to layer with some kind of thin fabric still... Although then you could already make a very thin glue cap all the same (although silicone would be flexible so that's a plus)

 

Saran wrap for covering the head and thin stretchy fabric for the cap are the best I've managed to come up with. I've heard of people also using dryer sheets instead of fabric!

 

@Lillith Wowww I never would have thought that latex would behave that way, but now that I think if it, I've only seen it used in temporary products like disposable gloves. I made my first wigs with Aleene's Fabric Fusion back in 2017, and as far as I've seen, there's been no breakdown or damage.

 

@industrious.jenn
Yes, it's unpredictable. I have some old doll shoes I made with a cast latex sole that are probably going on fifteen years now and while they have shrunk a bit, they are not completey dead. On the other end of the extreeme I've had things starting to show signs of ageing almost right away. True, those have probably been caused by something external, but when that can be as simple things as light, heat and humidity it's very hard to track exactly what went wrong.
My friends and I often joke about developeing superstisions around how and when to do latex jobs, like what did we have for dinner and what phase is the moon in? Because how else do you explain why seemingly similar projects behave to differently?

 

Yes, I'm sure there are better and worse products out there. Some will already have things added to them to make them behave a certain way and the exact proportions of ingredients probably vary a bit. I haven't purchased latex in years, so I'm not much help there.
Never work wtih latex when the moon is full. Unless you had pancakes last thursday, then you'll probably be fine.

 

@Lillith 's occult descriptions of latex have made me very curious about the material I'd also add that sometimes it's worth taking the plunge to try new materials out regardless of the doubts - maybe latex is the thing you need! And if it's not, you'll know a little bit more about what you want after testing it out.

 

I mean, short term it does work, very well. It's just long term that it can cause trouble. As long as it's for your own doll and you keep an eye at it, it's fairly risk free.
The only thing I would recommend against is putting it on a doll and forgetting about it for years, or selling/gifting it to someone who is not informed of the drawbacks.

Oh, and I would not put liquid latex straight on the bare doll. Remember what I said about the oxidization? latex is mildly acidic and especially when liquid that can speed up the oxidization of the doll surface as well, causing premature yellowing. This is not a certain thing, but an increased risk and the effect may not show up for some time, so it won't show up when doing short term tests. Talcum on the inside of the finished wig is also a good idea to keep the wig from sticking, especcially during storage (did you know that fresh latex, even after curing, can still fuse with itself?)
And this may be obvious, but... Use nitril or vinyl gloves, not latex, because the liquid latex can weaken the latex in the glove. Guess how I know that?

 

Looking at the problem of the fit of the wigs I wonder if you could make or find something a little smaller than your dolls head to make your wig on. In theory the finished wig would be a little smaller and should fit better.

 

A styrofoam ball, perhaps?

 

I've sometimes added a few stripes of hot glue inside the wig to make it tighter, but it's still not as great as using a good ol' silicone cap underneath

 

I'd try a little bit of hot glue in that case! I find that it doesn't have a great grip on resin but it might be good doubled up with the silicone cap

 

Popping in as a wig maker ~
I've used fabric glue, white glue, wood glue, and masking latex. I LOVE latex. Obviously there's always fabric involved, and I cover the doll with plastic wrap while making the wig. But My older wigs (only 2019) are still just fine...if you ignore the amateur mistakes in them. I think using the tulle/fabric base is what keeps it strong though. I don't believe it would stay sturdy or reliable without the fabric.

Wood glue gets brittle and shrinks. That was a waste of my time, LOL. Fabric glue, mod podge, and white glue are fine. They just take a decent amount of time to dry and don't appreciate moisture.