shrinky dinks!

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I'm sorry this is only a question and delete if you feel necessary but I could use some help.
I bought Shrinky Dinks today at a craft store but they weren't what I expected. They're flat and while the one side is clear and smooth, the other side is a whiteish paper (I think you all have an idea what I'm talking about).
Now.. this may sound completely silly but when I cook them and they shrink, will they stay completely flat? I had the thought in my head that they were slightly thicker than what they are now, which seems like a slice of paper. Are there other brands where the material is a few centimeters thick instead of paper like?
Also, if I don't put colour on it, does the finished product come out completely clear or does it come out completely white or does the stay out it is, with a white paperly look on one side and clear on the other?
I'll post some pictures if that'll help make my questions more clear but if anyone has some words of advice, I could really use it!
Thank you! <3
(and ps. I did look in the memories about Shrinky Dinks but they didn't really help.. at all. The one entry where someone made a 3D cat and cow is kind of what my Shrinky Dink paper looks like but those animals are thick (which is one of my questions) so I wasn't sure if it was the same).