A standard or non-layered tattoo is what 95% of all the tattooers out there are doing. Very few use or truly understand all the benefits of layering.
Here I compare a photo of a tattoo I did with another that was sent to me as reference by a client some time ago. My apologies for the low res photo of mine, as well as to the original artist of the non-layered work whoever you are.
My layered tattoo in this photo is several years healed in this photo as is the standard example.
Notice how fresh and new the layered tattoo still looks. The color is milky and thick and vibrant. Even after years of abuse in the sun. In the other one notice how dull and washed out it is. Even when done well, color will break apart little by little over time and show open spots, imperfections, patchyness and thin color around pores and such. It is the nature of the skin and a tattoo. Tattooing is an imperfect art by nature. The medium itself is in a constant state of degradation.
Below is the full explaination of Layering and its purpose, please read it through so you fully understand.
Layering is very different from doing touch ups, or even just going over the same exact stuff again. Touch ups are for ink lost to poor healing, aging or poor execution.
Layering can be done with any style of image. It is as effective at making color ultra vibrant and smooth as it is at making black and grey supernaturally milky thick and soft.
It means building up the colors over several passes, aka seperate sittings. Not unlike building up an oil painting to add depth and nuance. It can allow subtle gradients, detail and color vibrancy that could never be expected to keep long term in any other way.
Think of it this way: one properly done pass over a tattoo that is healed perfectly results in "x" amount of ink (most likely 60%-80%) being left in the skin after healing. Even a entirely successful heal unavoidably reduces the amount of pigment left in the skin compared to its freshly done state.
So with layering you pass over an area two or maybe three times (depending on the desired effect), in separate sittings, each after it is well healed from the previous time, this means you are not only compensating for the amount of pigment lost/absorbed, etc., but making sure its at the highest possible amount that the person's skin can effectively hold, but it also means that you now have a whole range of effects, textures, patterns, details and subtleties that would not be available (at least not in a long lasting way) without the added efforts.
That is the basic concept of layering but its actually more complex than that. Because after a certain number of well planned and well healed passes in a short enough time, anything additional would be redundant and useless, even causing excess trauma or scarring. The common theory in tattooing is that under perfect conditions, one perfect pass with one perfect heal results in a high color retention, and layering isnt even needed or desired. A highly skilled tattooist knows how to cater to this and will be able to adjust the art to stay within the range limits of this standard theory while still being able to make graphically powerful and long lasting imagery. Believe it or not that can be much harder than it sounds. This is particularly true in traditional or standard tattooing styles where expediency is often considered to be more important than the resulting effects, innovation, creative options or saturation. This leaves a lot of room for error and boxes in the range of depth, detail and effects to what has up to more recent years been very common. Reaching further has its advantages.
There exists a large range of options between a fully layered and satiated piece and a standard one shot tattoo. Sometimes certain areas can be intentionally left unlayerd in a piece so that the layered areas by comparison look way more vibrant in the finished product, helping with visual priority and depth.
Yet another factor is that the skin the tattoo is inserted into is aging and deteriorating and spreading at the same rate, whether the tattoo is layered or not. A layered tattoo can't stop the skin it's in from doing the same thing an unlayered tattoo's skin would do. layering, if done well, just gives it the highest possible chance for the longest possible period of looking saturated.
Any tattoo after significant enough amount of time, say 15-30 years, depending on the individual, needs to be "freshened up." In the same way that anything you ever want to keep nice, a car, a home, requires maintenance.
Think of it this way, an average tattoo that gets average wear and tear looks brand new for about a year, maybe two if a person has the right skin. After that it will appear in varying degrees of lighter and fuzzier depending on the years from application. 10-20 years in redoing the tattoo resets this process to some degree. This is all normal. Now with a well layered tattoo you will still need some maintenance years in, but it is likely to be twice as long before the degradation reaches as dramatic an effect as the same tattoo would if applied in a standard style. The real bonus to this is that the layered tattoo will keep that first year fresh look for up to TEN years! In an average 40 year period a standard tattoo would be done twice, looked perfect for two separate years and acceptable for another ten to fifteen, also split up. That same tattoo done layered includes that same amount of work, just all up front. That layered tattoo would look perfect for TEN and acceptable for another thirty, consistently, even though the same amount of time money and pain were expended by this collector the layered tattoo collector clearly got the better deal.
And here is the real kicker, once you open up to layering there are effects, patterns and textures available to you that simply would not keep if applied in a standard style. The art is now capable of evolving to a higher state. Including oil painted looking softness and saturation and depth that most people would have never associated with tattooing in the past.
This means a whole world of options is now available to you. There are certainly still limitations. The medium, the skin has natural limitations that need to be respected so these techniques should only be applied by an experienced layering expert. The skin can only take between three and four layers before scarring or changing skin texture/density can become an issue. For this reason my methods keep to effectively planning 2-1/2 layers. It efficiently achieves all the benefits while steering clear of overworking skin and bogging down the completion. I feel that any special effect and density can be achieved efficiently in this range by an experienced layering artist that knows how to keep expediency and effectiveness a priority. Not to mention the comfort and budget of the client. Because of this, being as efficient as possible to minimize your pain, time or cost will always be one of my top priorities, but know that even though this is important that I will always put quality and the wellbeing of the art first.
I am always learning new styles and striving to become a better artist as well as learning faster and more effective techniques. When people invest the kind of time involved in a layering project I know that every minute counts.
i personally developed my own style to accomodate my own working speeds and methods, on larger multi sitting pieces. For example, when starting a sleeve that wont be done for one year, if you colored one area of it completely on the first sitting, then never touched that "finished" area again for the whole rest of the year that sleeve was in progress, by the time you finish, the stuff you did at the end will have had less aging time, and thus will tend to look brighter, bolder, more saturated than the spot you did one or two years ago and didnt touch since. This is made more dramatic if the person's skin has seen a lot of sun in the meantime. Working over the entire piece in layers, moving back and forth between areas over different sittings, and layering with a well laid out plan is a wiser approach to doing large work that solves this issue as well as others. but its not necessarily best for every piece, for every tattoo artist, or for every collector, or even for every style of tattoo art. its a complex issue, as you can see.
Your option of layering not only reduces the amount of touch up work you will need to keep it looking nice, but offers a much better and more vibrant tattoo in the mean time as well. Of course that means more time and money as well as more discomfort getting tattooed as a trade off. I have no qualms working in either style but it is vitally important to decide which route to take before starting. It will require an entirely different approach for a layered tattoo as it is not (as many people believe) just going over it again. Please tell me which you prefer before we start so I can allot you the correct amount of time.