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I have the Sizzix Big Shot and the Cricut expression. And I love them both! The Big Shot die cuts and embosses pretty much any brand of die/embossing folder.
There are two types of embossing, wet and dry. Wet embossing is done with a heat gun, embossing powder and embossing ink. There are a few different ways to wet, you can use your stamps and stamp with the ink and then pour the powder and heat with your heat tool, or you can press the ink directly to the item you are embossing.
Dry embossing is done with a machine that you run a folder through and it creates a raised textured pattern on your paper.
The sizzix dies are really great, there are some lovely dies and embossing folders out there.
I also love my cricut, I only have 5 carts for it and can create so much with just those. If you are looking to do titles mainly with it you can get a font cart and there are several options for fonts on each, all similar but still sligtly different. Then each cart I have gotten has had a font on it as well as tons of different shapes.
There is a computer program you can use with your cricut but I haven't found a need for it yet-but I have only had mine for a couple of months.
I started with my sizzix though and would have been just fine only using that, but DH got me my cricut for Christmas. I still use my big shot just as much as my cricut, if not more!