If a piece of art is to be labeled as having any "value" at all it is what is said about it that establishes it as a work worthy of an individuals attention.
In other words ... if you see a picture and it relates to you in some way (this can be either positively or negatively) - then you should say so ... and write it down.
So once one remark has been made then others will follow ... plus other people will look at the work and make their own minds up about it, and they will also read about what you have said ... and they will include your critique in their weighing up of the image.
I am not necessarily talking only about financial worth, no, here is a far greater opportunity which is all inclusive, wonderfully mutual, and offers the chance for anyone - and everyone ... to add to the worthiness of any piece of art - and eventually to the whole of society. What YOU have to say about a particular artwork is very important ... even vital not only to the work, or the artist, or that particular type of work, or to your locality, or to your region, or to your country ... but to the World! (I am referring here to the butterfly wing beat theory ... if you don't know about it then you must look it up ... it really puts value onto the individual within a world context ... fantastic - but I believe it's true).
Let's look at this in a bit more detail, first from the artist's point of view ...
If, when you exhibit your art, you value what people have to say about your work (and I don't mean if you want everyone to love everything you do otherwise you will sulk and withdraw into yourself), and are happy for observers to voice their opinion about it - make sure you have a visitors book easily available for any remarks to be made (remember ... even someone who only wants to deface the book is actually saying something about themselves - and their society ... and your work might be evoking a challenge to them so much that their only response can be a defensive one such as vandalism - therefore even this has a value in itself - and strangely actually places a value upon your work). These can have a use later on in publicity, and in some cases can be seen as endorsements for your style of work.
If you have a website then a well placed, easy to understand and use, guest-book or visitors book, or comments page are very useful reference points for you and your work. If visitors refer to a particular image then their critique might be worthy of adding to the page that the picture is on. That way other observers can get to read observations coming from different points of view. Of course, if a visitor does not want to be influenced - then they can just simply ignore anything that is written. However, others may well find such additional information from the "man-in-the-street" helpful to them as they try to assimilate what they see. What is written will be of far greater value to them - and to you the artist in may other areas too. And if you are trying to sell your work then a timely encouraging comment from a third party might persuade an otherwise hesitant buyer into making that sort after commitment.
Now from the visitors point of view ...
It is a truly wonderful thing to be "touched" by a piece of art in a gallery. When ever I have found myself slowly being drawn into a painting I immediately want to verbalize what I am receiving - I might want to shout or laugh loudly ... but more likely I would want to put down in writing a description of what I am seeing, what I am feeling, and what kind of inspiration I might begin to cultivate ... and what intention I might want to start getting in motion (which is why I always carry a notepad around with me).
So I would encourage, even exhort, the viewer not to just take a back step and move on to another picture. But rather I want them to commit their thoughts, frustrations, emotions, decisions, resolutions ... anything which has come directly from looking at a piece of art, commit these to paper - find the visitors book and, if necessary, fill it with your reactions to the work. By doing this the visitor is rightly placing themselves into the "experts" chair. So any thoughts and points of view are worthy of note. If you have a view on a piece of work then it should be heard.
It is the same - or should be - when visiting a website. In fact it can be easier to make an anonymous comment on the internet. A lot of sites give you the opportunity to make a comment without having to give your name, email address - or any information other than the words you want to type. So if you are that sort of person then don't be afraid but try to get into the habit of writing down your views. You might actually WANT to reveal who you are or put down your area of expertise ... be it the university professor or the "public highway hygiene technician" ... because what you say matters ... whoever you are.
What will happen here is that as comments are made and attached to a work others will read them and, having viewed the piece themselves, they will make their own point of view whether for or against other comments ... and the work will gain its own merit from what is said.
So while the top artists are busy vying for that hallowed multi-millionaire-and-totally-famous-artists kind of place - the rest of us can get on and work, and receive a much more valuable encouragement ... that of the humble, if not down-to-earth, endorsements from our fellow human beings.
Don't be afraid ... be truthful ... tell it like it is ... and watch what happens.
