For example, I'll start with one method I've mentioned recently in another thread - using coin albums to intentionally tone coins. With that method there's basically 2 ways to do it. You can buy the albums, that are well known for producing coins with gorgeous toning, place coins in them and simply wait for it to happen, or not happen as the case may be. But, you do this quite intentionally and for no other reason than hopefully to cause the coins to tone. Is that artificial or natural toning ? Second way, buy the same albums, put the same coins in them, store the album in a location with high humidity and higher than normal temperatures. Is that artificial toning or is it natural ? Next you can do these same things and both ways, using normal storage or storage with increased humidity and temperature, only by using small manila coin envelopes, or by wrapping the coins in tissue paper, or by using the old original mint packaging, flat cardboard coin holders, used with mint sets in the 40's and 50's. Or, you can buy old original coin bags, place selected coins in them, and then just wait and see what happens. Or, again store those coins in the old original bags but in an area with increased humidity and temperature. Or, you can purchase some of the old tab holders, and use them, in the same 2 ways. Or, paper coin rolls, old or new, and use them in the same 2 ways. Are any of these things artificial toning or are they natural toning ? And can any of you tell any difference between the coins toned in any of the ways mentioned above ? Any and all of them are very, very well known for producing coins with gorgeous toning. Toning that is and always has been widely accepted as being completely natural, and highly desirable. Using the old mint bags you can even reproduce highly desirable textile toning if you want. But is it natural toning if you quite intentionally do any or all of these things ? Each and every one of you can and probably will answer that question, if for nobody else than yourself. But when ya do, please do so with this understanding. Any and all toning on coins occurs because of the gasses the coins are exposed to. Those gasses can be in the very air we breathe, or those gasses can be being put off by the items the coins stored in or near. Albums, coin envelopes, tissue paper, old cardboard mint set holders, old mint coin bags, paper coin rolls, any and all of these things put off gasses and it is those gasses that tone the coins. Not direct contact with the items. Yes, direct contact can alter the pattern of the toning sometimes, like textile toning and end roll toning, but it is not the direct contact that causes the toning itself - it is the gasses that do that. I suspect that a lot of you are going to say that this, all of this above, is all natural toning. Others will say it's artificial. So now, just imagine, you build yourself a sealed box, with say 3 valves installed, one to pump air out, one to pump gasses and humidity in, and one to release it. You place coins in that box, and introduce the very same gasses put off by any of the items listed above, and you control and temperature and humidity. You can even have the coins in one of those old coin bags so you can reproduce textile toning, inside the box. These coins are going to tone, and some of it, maybe much of it will be quite gorgeous. If you use the same gasses, the coins ARE going to tone the same way. And by using the different gasses, you can even be selective in the colors you produce. And if some of those coins are stacked partially on top of each other, you can easily produce crescent toning. Or if the coins are laid flat, monochromatic toning - double or single sided if you turn them over or not. But is it natural or artificial toning ? And can any of you, even 1, say with any degree of certainty, that this toning is any different than the toning you have always considered natural toning ? Bear in mind, your intention in all of the cases mentioned above was exactly the same - to cause and create toning on the coins. In every single case you are using the exact same things to cause the toning. The only differences are your intent and the speed at which the toning occurs. Also bear in mind that you now know many different ways that toning of virtually any kind can readily and quite easily be reproduced at will. And in a very short time - literally hours. So what's your answer ?