There are a couple of things we should think about before we choose a cookie sheet, because there are many options out there! Do you want the sheet to be totally flat, or have raised edges to prevent things from spilling off? Will you use the sheet just for cookies, or will you cook other foods (like vegetables) on it? I personally prefer a cookie sheet that can be used for more than just cookies, so I go for pans that are large with raised edges.

Other qualities to pay attention to are thickness, material, and nonstick coatings. Cookie sheets are nice for making cookies because they heat up and cool down quickly. To achieve this, they are usually made of aluminum, which is lightweight, inexpensive, and heats up quickly. The pans are also usually pretty thin, but they come in a range of thicknesses. It is good to find one that is not too thick (so that it heats up quickly) but one that is not too thin (so that the bottom of the cookies don't burn and so that the pan doesn't warp in the oven).

Cookie sheets sometimes have a "gauge", or thickness, reported on the label. A good sturdy pan will fall between 10 and 18 gauge. If you can bend the pan easily, then it is probably too thin and you'll risk having burned cookies!

Once you find a good thick sheet, the next choice is to decide if you want a nonstick coating or "natural" (no coating). Nonstick coatings make for easier cleanup, but they can cause your cookies to spread out a bit more because they are slick. They can also make your cooking times a little faster because they are dark grey or black in color. Natural pans are a bit harder to clean because food can bake on and harden onto the pan, but your cookies won't spread out too much. Also, most recipes use cooking times assuming you have a natural cookie sheet. Nonstick versus natural is totally up to you! Both will make for good treats. Happy baking!

Great question! Metal cookie sheets, specifically aluminum are great to help bake.

Aluminum has great thermal conductivity, which means heat passes through the pan into your cookies. They are evenly cooking. Stainless steel and silicone sheets work as well, and while easier to clean have worse thermal conductivity. Be careful fully bake your cookies before eating! For shape, you want a cookie sheet with raised edges. This allows cookies to slide off easily. Any shallow rectangular pan will work. Lighter colored cookie sheets absorb less heat. Use lighter pans for cookies and darker pans for pizza. Hope you make delicious cookies.

My son is a very serious cook, and he just made Halloween cookies. He says the best cookie sheet is a heavy aluminum one, because aluminum conducts heat well - and if it's heavy, it will be sturdy. His has edges, which makes sense, because you don't want cookie dough to drip into the oven. His is uncoated aluminum and rectangular. Rectangular is good, because it's easier to arrange lots of cookies on a rectangular pan than on a round one. It's a 'half-sheet' size - 18 in x 13 in - which is a normal size. A 'whole sheet' is something a restaurant or bakery would use.

To find out what kind of cookie sheet is best for making cookies, we can do some experiments. The color probably will not matter as much as material, shape, and thickness, but the basic design of the experiment would be this:

We choose a single type of cookie on which to do the test. (During the first test, we may want a simpler cookie with no chunky ingredients such as chocolate chips.) We mix the ingredients well and form the cookies on the cookie sheets we want to test, making sure that all cookies have the same amount of dough and are shaped the same way. Then we put the cookie sheets in the oven on the same rack - this is important because we want the same amount of heat AND the same kind of distribution of heat for all the cookies so that the only difference is the cookie sheet - and bake them.

Afterwards, we observe which cookie sheet or sheets gave the best cookies. Of course, the word "best" will mean different things for different kinds of cookies.

We can imagine that thinner cookie sheets give better crispy cookies while thicker sheets may help us bake softer, chewier cookies.

It shouldn't matter. Some cookie sheets may have the issue that the cookies will stick to the pan, but if the cookies contain any fat (e.g. butter), then that shouldn't be an issue.

Metal is less likely to melt in an oven than plastic, and less likely to pollute the cookies.