Soft Blend Silicones

Let’s talk about Soft Blends in Silicone.

As a collector and painter for many years, the shore of silicone is very important to me. It determines how soft and squishy the silicone will be and how easy it’s going to paint. I maintain the opinion that the softer the silicone, the more difficult it is to paint and handle. Softer silicone also needs a great amount of care when it comes to holding and dressing.

For the last few years, very, very soft silicone has become super popular and before I got into the molding and casting business when I went to order a silicone kit that was out of the ordinary soft, the terms that were used to chose which you wanted were ‘Soft Blend’ and ‘Marshmellow’. Soft Blend was softer than Eco20 and Marshmellow was softer than Soft Blend.

I also knew that a Soft Blend and Marshmellow were tailored to its castor because both are just individual recipes of Silicone and Slacker.  That is how I knew it to be for a very long time.

But I recently read such an informative post by expert molder and caster, Kristin Englert on the differences of Soft Blend Silicones, and with her permission, she has allowed me to quote her.

‘ Hello all. I am a molder and caster, as most of you know, so I get the question “Do you have marshmallow silicone” or something similar Multiple times a day. OKAY…. Let’s set the record straight here. THERE IS NO SUCH PRODUCT called marshmallow silicone!!! What it is, is a softer than Ecoflex 10 silicone that is made by using slacker. I don’t know why this seems to be a “secret” in the industry, one-click on Smooth On’s website tells you exactly what to use.

 Straight from smooth on’s website ….. Slacker® is one component of translucent clear fluid that is added to our translucent platinum-cure silicones such as Dragon Skin® and Ecoflex® products. Slacker® will change the “feel” of the silicone rubber to a softer and more “flesh-like” material. It also alters the rebound properties of the silicone, making it feel more like human tissue.

SO in other words… soft blend silicones are made with SLACKER and platinum silicone. Now, marshmallow silicone is a term used by multiple artists that can mean a wide range of things. It can mean just a slight soft blend, a little bit of slacker used. It can mean a super soft blend, more than a little slacker used… or it can mean an extremely squishy ( bend your doll in half) soft blend… lots more than a little used (not my recommendation). SO the thing is, you can’t really ask a molder “is your silicone marshmallow” without knowing the exact percentages used. NOW… with that….Smooth on has recommendations the amount to use… TAKE IN MIND… this is not a pure science. Since many use EcoFlex 20 (which already has softener in it, which is why it is softer than EcoFlex 30 and 50)… percentages on slacker will vary. I personally would NEVER use 50% slacker on an Eco20, as the baby would be very very fragile. However on a higher Ecoflex like 50 or dragon skin, you could get away with that ratio if you want that EXTREME softness. One thing to remember is you are changing the chemical make up of the silicone. The higher percentage of slacker added, the more fragile your casting becomes.

1 Part A + 1 Part B + 1 Part Slacker® Result – “Tacky”
1 Part A + 1 Part B + 2 Parts Slacker® Result – “Very Tacky”
1 Part A + 1 Part B + 3 Parts Slacker® Result – “Extremely Tacky / Gel-like” (NEVER FOR A DOLL)

1 Part A + 1 Part B + 4 Parts Slacker® Result – “Super Soft Tacky Silicone Gel” (NEVER FOR A DOLL)

SO what does this all mean?? It means Soft Blend and Marshmallow silicone are the same thing. They are a platinum silicone / Slacker mix. EVERY molder and caster has his or her own recipe. You can’t ask one caster if their “soft blend” feels like “so and so’s soft blend”, unless you know the percentage of slacker that molder and caster uses. Some casters “soft blend” feels the exact same of what another caster calls “Marshmallow silicone”. Watching a movie, or seeing a photo of how one looks when pushed in, doesn’t give you any information. Fun to see, fun to watch, but no real information on what that casting feels like. This is why when asked I don’t make a video pushing in my castings tummies (as this also makes a huge difference on how thick the tummy area was sculpted). 

Also to be mentioned. Smooth On’s Ecoflex 20 has a range of shore hardness. Smooth on gives a -10/+10 shore hardness allowance either direction on their silicone products. Meaning you can get a batch of ecoflex 20 that feels more like a 10 or 30. This is something us caster have to deal with on a “per order” purchase, as the silicone is very inconsistent. I do my very best to fix that range when I end up with a batch that is too soft or too hard, for my “eco 20” standard. This is why you may see posts or hear things like “I got a baby that feels harder than ecoflex 20 but the seller said it is not”.. That is due to smooth on’s allowance of their eco20. I myself have even received questions on eco 20 I have sent in the past…and I assure you, I don’t buy eco 30 to cast dolls in.

I have noticed that the higher the slacker content creates an unstable painting surface and structure. These dolls need extra prep and silicone pore opening (as in using Novocs Gloss all over the casting to open those pores), or they will have a harder time taking paint. They will take paint but need an experienced painter. As a result I will not typically cast a “super soft blend” for just anyone. Only an experienced painter who knows how to paint and how to handle a baby that soft. Like I said before, they are also much more fragile. They are more prone to tearing, and stretching.’ 

There you go!  Such great information! Thank you, Kristin. This will help us all!!!

2 thoughts on “Soft Blend Silicones

  1. Lori FitzgeraldLeger says:

    Thank you Crystal! I really appreciate your research on the silicone issues and how some caster use a different (recipe)
    Mixture of things I’ve never heard about. I’m a doll collector and I’ve always wanted a Silicone babydoll to ad to my collection of reborns and other older types of dolls,the cherry on top!
    And I see some that are EXTREMELY EXPENSIVE, 12.000 WAS THE MOST IVE SEEN.I DO UNDERSTAND THE ART BEHIND REBORNING EITHER VINYL OR SILICONE AND YOUVE WRITTEN HOW DIFFICULT IT CAN BE FOR THE PAINTS TO ADHEAR TO SILICONE AND I DO APPRECIATE ALL THE SWEAT & TEARS INVOLVED WITH THE ART PROCESS OF CREATING A SYMBOL OF LIFE , AND SOME LOOK AS IF THEY ARE!
    I REALLY ENJOYED THIS ARTICLE AT 2:00 am as I break from Crochet baby items . One day I will own a life like silicone babydoll .
    Thanx again and take care!!

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