Yes, both are vitreous enamels, just as a Ford and a Dodge are both automobiles. Both are different types of the same general thing. People who drive automobiles have a preference, just as those who enamel also have a preference. The ability to drive an automobile, like the ability to enamel, depends completely upon the individual, providing everything else is in good working order. Unlike enameling, driving requires a license. The license is a document that indicated that basic skills for driving and knowledge of the rules of the road have been met at a particular point in time. Any average person can learn to drive, just as any one can learn to enamel. If it be a Ford or Dodge, lead bearing or lead free enamel, the simple facts are that it doesn't matter which are used. Both are just what they are, a car and an enamel. Neither make a professional driver or enamelist. It is up to the individual, through his or her skill and methods of operation that such a level of status or state of satisfaction is acquired.
Somewhere amid illusion, delusion, and fact everyone becomes predisposed. Attitude, accessibility, learning and necessity are elements that influence and categorize actions into levels that typify expression and display. There are obviously differences between a Rolls Royce and a Hyundai. However, both are automobiles. There is comfort or discomfort to both eye and body depending upon personal preference, yet both can transport a person from one point to another point. It is a matter of which is desired, which is survived, which fulfills the requirements that are needed to be met. The question is not about 'how' one arrived, but about that they arrived barring accident. The enamel used is not the question. Did what was used meet the standards necessary to have been used in the first place? Did the material allow the user to travel from one point to another without accident? If an accident did occur, was it the fault of the driver or the car; the enamelist or the enamel? Which 'maker' is most culpable? Every maker is capable of producing a product that is less than standard or that blurs differentiation. Conclusions can not be jumped to nor assumed based on outright prejudice. No two products ever produced are ever completely the same, there may however be a vast amount of similarities that liken one to another. The fact remains that there are more variables with the user than the product used when it comes down to the ability to enamel.
The question about the differences between lead bearing and lead free enamel is the same as the questions about the difference between lead bearing and lead bearing, or between lead free and lead free. There are more differences between enamelists than there are between enamels when it comes to fiction versus fact. Assuming that both of what is being compared are of equal quality, there can be only one source for any major disparity aside from the initial manufacture of a specific vitreous enamel batch, in which case the results would be generally the same. The ability and knowledge of the person enameling becomes the central issue and source for the differences aside from the technical/chemical facts.
When a person only knows the tricks of the trade without knowing the basic logic of the processes, that person is a victim to every iota of difference regardless of any previous instance of success.
Unfortunately, the majority of those actually applying vitreous enamel to metal and firing such a piece only know the 'step-by-step' for that process or those pieces. There are few, if any, professional enamelists currently enameling in either art or industry that do not rely on data that they individually have not experienced. All mankind, must reference knowledge and experience of the previously pondered, both from history and themselves. Procedural information does not always transfer from one enamel to another, nor does it transfer from one process or project to another. Most of what has been taught is procedural and in accord only to the limitations of the teacher. Examples of this abound and are even written into books where the printed word is read as if it were truth. Very little of what is being currently written and published for or taught to the artist and or leisure hobbyist is indicative of anything other than 'a personal approach'; without supporting logic or documentation that relates to either the history of or the technology within the context of that which has been, is, or can be.
Not a day goes by where one does not learn, have reinforced, or discover additional facts and relationships about the whole process of enameling. Continual enlightenment pushes further and further until all is a boundless territory of choice. One should reel under all of the potentials and possibilities from which to choose. If for some reason one becomes locked into a death like grip of being helplessly bound to only one choice and the repetitive procedures neither add or improve either the quality or efficiency of their work, then it is time to question whether a trap has been fallen into or not. If the same routine with the same results for the same reason does not bring joy, to the intensive endeavor of enameling, then the inhibiting factors must be removed.
It does not matter which vitreous enamel a person uses. It matters not whether it is opaque or black or transparent or green or red or ruby or lead bearing or for glass or lead free or for aluminum or in liquid form, it all makes no difference providing that the whole of that which is produced is aesthetic for the purpose it was created.
Over the past twenty five or so years I have used for personal work and taught with both lead bearing and lead free vitreous enamel. Today I still use both, however the majority of my current work is with that of the lead free material. I advise and consult individuals and companies about vitreous enamel; problems and procedures, lead bearing and lead free, it matters not as long as quality control is gained. By choice I currently teach with lead free material because of the advantages I feel it has to offer and to be current or abreast with technological advancements. I make no claims about being more correct, any person working with enamel on a constant basis improves with insight providing they are not hampered by preconceived authority. Again by choice I use that enamel which will serve my purpose for the best results with the limits of my knowledge and abilities.
Yes, I remember the good old days when 108 transparent Forsythia yellow could solve all of my problems and I still have some of that lead bearing uranium colored enamel tucked away. But times have changed and I have changed and that bag of enamel does not dictate to me what I can do, even though I've more than enough to create many pieces.
The consternation is not about lead versus non lead enamel, it is about change and the ability to change for those who have been working with and dependent upon lead bearing enamels for a number of years. To that problem it can only be said that constructive criticism is far more positive than egocentric cries of foul play.
When it comes to art does it matter if it is lead bearing or lead free? Simply put, the answer is no. The responsibility for art belongs first and foremost to the artist, the creative person who contributes through forms of expression that which can not be denied worth. Like it or not, there are very few who are that select, most of us struggle to rise above the average within any given field. The question has merit only in theory. Worth does not depend upon any one material, rather it depends wholly upon the individual at any given point in time.
When it comes to safety does it matter if it is lead bearing or lead free? Again simply put, the answer is no. When it comes to personal, private, or public safety, everything must be considered toxic. Everything harbors potential danger. If not in itself, then in its confrontation with man. Danger can not be removed if one anticipates living on this earth. Laws were created to protect man against himself. Laws were also created to socialize groups of people into organized cultures of hierarchy. We now have laws that reduce our exposure to lead, but that does not mean that we live in a safer world when one considers the more rampant killers.
When Thompson Enamel stopped producing lead bearing vitreous enamel for the artist in 1990, it was the last and only company in the United States doing so. Laws had made it unprofitable in terms of business and it is important not to forget that Thompson Enamel is a business first. They sell a product for profit, that is their business.
The absence of a US manufacturer will not detour the enamelist, nor will the use of lead free vitreous enamel decrease the quality level of items produced. The replacement of lead bearing with lead free vitreous enamel will reduce the problem of exposure to lead due to sloppy hygiene and careless work procedures for those using lead free material, but if hygiene and work procedures are not also improved, some other toxic material will probably take its place. Only the individual can improve his or her work habits and so to speak, clean up their act.
As to the specific differences between lead bearing and lead free, their advantages will be listed first. This listing will compare those lead bearing enamels that were produced by Thompson Enamel with the lead free enamel produced by the same company. This comparison does not include or preclude similarities for lead bearing materials produced by foreign manufacture. Such a comparison would probably have an equal number of similar facts among the more common types and colors of vitreous enamel. These differences must be stated in generalizations because no two enamels are alike, unless they are from the same batch. Also, for example, a transparent red made from gold and a transparent red made from cadmium selenium, while both transparent and red and vitreous will always be considerably different under all conditions whether they contain lead or not.
LEAD FREE VITREOUS ENAMEL ADVANTAGES
Lead free will by volume weigh less
Lead free will be more acid resistant.
Lead free may be ever so slightly harder (scratch ability).
Lead free may absorb more copper oxide from the metal surface.
Lead free may have a larger coefficient of thermal expansion.
Lead free will have less water solubility.
Lead free will have a slightly higher softening temperature.
Lead free opaques will have less color variation due to different firing time/temperature relationship.
LEAD FREE AND LEAD BEARING EQUALITIES
Index of refraction.
LEAD BEARING ADVANTAGES
Lead bearing has a slightly decreased skin texture.
Lead bearing currently has a greater color selection.
Lead bearing has lead arsenate opal colors.