It really depends on the quality & thickness of the silicone. How silicone molds are made affects the quality. Interestingly, there are
3 curing methods for silicone and that will impact the quality of the mold.
Some are so thin, they fall inward into the mold without something to hold it in place. I have one like that & I use blue painter's tape
* to hold it in place; it works for a couple of uses, then I have to replace it; even clips don't hold it well enough for a smooth line.
But I also have a couple that have super thick silicone liners that never bow unless out of the holder & filled with water when I am washing them. (See below re: ED molds.)
And then of course, there are some with in-between thicknesses.
The
Mighty Mold I have is free-standing with no outer box, and it has a Velcro strap to hold it in place so it won't bow or leak. The Mighty Mold is a fit-together type mold. The silicone is platinum cured. It is a small tester mold.
From what I understand,
Nurture Soap green silicone mold liners are made of a high quality silicone. I don't own one, but the claim that they will last your lifetime is certainly impressive. The liners are vary in thickness; some are 0.18 inches thick; some are 0.13 inches thick; the slab liner is 0.25 inches thick. So it depends on which mold you get, how thick it is.
The Essential Depot silicone mold walls are 0.25 inches thick and I do own a couple of them. ED claims that they are
strong enough to withstand thousands of uses; I doubt I will use mine a thousand times each, but it is another impressive claim. The only thing I don't like about the ED molds are the size of the soap, if cut normally, but by altering the way I cut my bars, I can get the size I prefer and travel sized soaps all from the same mold.
* I tape the entire length of the long end of the silicone, draping it over the wooden box; then overlapping more tape to the wooden box; then a ring around the entire outer circumfrance of the box which holds the tape in place so it cannot slip, confines it in place.
