They usually use fondant
Marzipan under fondant icing makes the cake too sweet, because fondant icing makes the cake too sweet on their own. It is better to use a buttercream with less sugar.
No. You do not have to put icing under the fondant on a cake. You can bake a cake and not put any icing on it and just put fondant on it if you wish. No law forces you to put icing on the cake. With that said, How do you plan to stop the icing at the edge of the fondant? Which will you apply first? Normally sugar in the the icing causes it to stick to the cake and also causes the fondant to stick to the icing. So if you have messy people eating your cakes and do not want the fondant to fall off the plates onto the rug as they walk around the living room at a party, it would be best to use icing as a glue.
It's a brand of fondant icing made by Bakels
If you are making icing, yes. If you are making a meringue, no.
Fondant is best for outdoor weddings.
food coloring
Fondant goes over icing that has been on a cake in the fridge.
the frosting
I have no idea about the cost of fondant. However, you can make an at-home version of fondant by melting icing to a liquidey consistency or by applying icing as it is from the tub to a still-hot cake. This will cause the icing to melt, but as you layer it, it will cool and form an icing that is more consistent with fondant, than the thick spread that is usually on cake.
Well first of all you need to have a particular shaped -out icing spread and if you watch many ADS (advertisments).You can see they always will say about icing spreaders. Cover the iced cake with a sheet of wax paper and smooth it out with your hand. Refrigerate the cake for awhile and peel off the wax paper once the icing has hardened. You will know it is ready when the icing does not stick to the paper. Another way to have the effect of smooth icing is to use fondant. It is like dough, but it is made mostly out of sugar and its easier than trying to get icing smooth..
If you are shaping the fondant into bite-sized pieces, which is the most common way of using it, you need an icing that will harden. Frostings made with butter, shortening or cream will not firm up, and neither will canned frostings. The easiest way to ice fondant is by melting some of the fondant itself in a double boiler, with any liquid from water to fruit juice, extracts or liqueur, using 1 tablespoon of liquid to one cup of fondant. It must be a liquid when you pour it. This icing firms up very quickly, so it must be poured smoothly and evenly over the pieces of fondant, which will need to be on a baking rack. If the icing starts to harden put it back to simmer, stirring all the while. You can also use a recipe for petit fours icing, and they are plentiful on cooking websites.