Plastic or fake looking skin comes up constantly among retouchers. I personally dislike it on photos. But there are many different types of plastic or fake looking skin. I will explain a few of the ones that I have experienced.
1. The "Blur" crazy wanna-be retoucher: We all have seen this on Deviantart.com, ModelMayhem.com, and other similar websites. Hopefully something like this never gets printed or published. Someone either takes the Blur Tool, Gaussian Blur, or Surface Blur to all of the skin on the subject. This technique if done moderately on a small web photo may be OK for most people. But a good publication can not accept this type of image work in high resolution.
2. The retoucher is good but the retouching customer wants that "smooth" look: This is just a simple case of "It's gone too far" it looks real but just a too perfect. Has this happened to me? Oh yes, more often then not do I get a client that wants more, more, and more. Sometimes a publication and sometimes a personal photo. I just don't attach my name to these particular jobs. In this case I am just the engineer and not the architect.
Retouching is mostly an art, but it's also a service. I think this is why we get so much debate on what looks right and wrong. It's up to the individual who is requesting or paying for the image to determine what is right or wrong for them. If you are looking into a professional career as a retoucher you should put your best work in your portfolio and let the client decide. If you are retouching to enhance your photography or for fun, do whatever you want. It's your art.
My recommendations for those trying to really learn how to retouch is to go on a case by case basis. Every photo, photographer, model, lighting setup, client, printer, or publication is different with different needs. You must learn to work with every type of photo presented to you and to make it look as realistic as possible and still meet their needs. Some high-end retouchers will only show work done in a professional studio setting with perfect even lighting and a model with almost flawless skin. Yes, these look amazing…. but is that all they can do? How much money can you make doing only one thing? There is not one right way to do retouching so learn all the techniques and know when to apply right it.
I hope to write some case based type retouching tutorials soon.