What is a Provenance and why do I need one?

I have attempted to insure my painting as a separate item and the insurance company has asked me to provide a provenance. What is a provenance and where do I get one?

Jill's answer

Hi David

A provenance certificate or statement is handy if you are insuring or re-selling a painting (eg at auction or privately). It is just a history of the work – ie who painted it, who has owned it over the years - and would probably include receipts of purchase and other supportive material.

Sometimes it will list where the painting has been exhibited and possibly provide extra information about its particular story, which might make it more valuable (ie if it were selected for a prestigious exhibition at, say, the Gallery of NSW) or in an artist’s retrospective exhibition or a travelling show. It is also a guard against forgeries (though what’s to stop someone forging a certificate I have no idea!).

In the case of your painting I imagine that the artist (or his/her agent) would have issued you with a receipt and the artist would have signed the painting. That should really be sufficient proof of ownership and authenticity. (It would also be a good idea to include a photograph and description, including frame, for your insurers).

Should your insurers require additional information about your painting I suggest that you contact the gallery where you purchased it and ask for a simple statement of your transaction. If you purchased it direct from the artist he or she should supply a similar statement.

For insurance purposes you may wish to check the current value of your painting. Sometimes that will be more than you paid for it or less (sorry, you don't want to hear that!). Check recent auctions to see selling prices of comparable works by the same artist but also consider replacement costs (ask your gallery or the artist). Then I guess you will weigh up the cost of insurance premiums against that information.

When we had our gallery, Port Douglas Gallery of Fine Art, in addition to a receipt, we would issue purchasers with a certificate which described the size and medium of the work, as well as its title. Also, as a caution to the new owner, a clause that copyright laws applied to the work was included, and the client was provided with a copy of the artist’s CV. I think we also noted whether freight and freight insurance were required. That was also useful for our own records.

If the painting subsequently changed hands several times, those transactions could have been added to the information that we provided, thus adding up to a solid 'provenance' for the painting.

I hope that helps you - and will satisfy your insurer!

Thanks for asking the question ; I hope the answer will also be of interest to others.



by: Anonymous

Pleased with the information. Never thought or considered insuring my works.

Good point and super explanation.

Ted E.

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Length of Golden Spiral

by Ajit Athle
(Pune, India)

In your interesting article about the Golden Spiral, you've mentioned that the total spiral length = 1.618 or thereabouts if the height of the initial rectangle is 1. There seems to be some error here. If the height, as you say, is 1 unit then the length of the spiral should be Pi/(2(1-k)) where k ~ 0.618 which would make the total length about 4.112398 units and this is not too difficult to prove. Here's a simple proof: Length of the spiral in the first square = 2Pi*1/4 = Pi/2. In the second square it would be = Pi*k/2 where k = 1 - (1+V5)/2~0.618. The total length of the spiral = (Pi/2)1+k+k^2+...=(Pi/2)(1/(1-k)= 4.112 approximately.


I made a mistake... sorry
by: Anonymous

In the last comment, I said that the series converge to (Phi - 1) / (1 - (Phi - 1)) = Phi, but I was wrong the correct answer is:

1 / (1 - (Phi - 1)) = 1 / (2 - Phi) = Phi^2

So the correct answer is (Pi / 2) * Phi^2 ~ 4.112398

some maths, I hope to be clear and easy to understand
by: Anonymous

As far as I understand what you're trying to do, it's to get the length of an infinite number of half semi-circumferences, all scaled down by a factor of (Phi - 1 ~ 0.618), right?

If you take a golden rectangle (1 x Phi) and draw an square (1 X 1) inside this rectangle, then you have the original golden rectangle divide in one square (1 x 1) and other golden rectangle ((Phi - 1) x 1), you can repeat this procedure with the new golden rectangle and always you get the same composition a square with a golden rectangle; now, if we pay attention to the scalation factor between each rectangle, it's easy to demonstrate that this factor is Phi - 1 always.

In each square we draw a circle arc to construct our "golden spiral" (but truly this is not a golden spiral, it looks like, but it's not. The real golden spiral is given by the polar equation: r(T) = Phi ^ (2/Pi) * T whew T is the angle and r is the radius as a function of the angle)

The length of a circumference is given b: c(r) = 2 * Pi * r

As we just have the half of a semi-circumference then we have to divide the formula by 4, so the function is transformed in: c'(r) = (Pi / 2) * r

Now we have to sum all the arc's:

If we fix the radius in 1 then we have:

golden spiral length = a0 + a1 + a2 + a3 + . . . + an + . . . + until you get tired.


a0 = c'(1) = c'((Phi - 1)^0) = (Pi / 2) * (Phi - 1)^0
a1 = c'((Phi - 1)) = c'((Phi - 1)^1) = (Pi / 2) * (Phi - 1)^1
a2 = c'((Phi - 1) * (Phi - 1)) = c'((Phi - 1)^2) = (Pi / 2) * (Phi - 1)^2
a3 = c'((Phi - 1) * (Phi - 1) * (Phi - 1)) = c'((Phi - 1)^3) = (Pi / 2) * (Phi - 1)^3
an = c'((Phi - 1) * (Phi - 1) * ... ) = c'((Phi - 1)^n) = (Pi / 2) * (Phi - 1)^n
until the end of this era.

Then we have to sum all these arcs :

golden spiral length = (Pi / 2) * (Phi - 1)^0 + (Phi - 1)^1 + (Phi - 1)^2 + (Phi - 1)^3 + ... + (Phi - 1)^n + ...

the second term in the last equation is a geometric series, and as (Phi - 1) < 1 then the sum converges, so we can rewrite this series as:

((Phi - 1)^0 + (Phi - 1)^1 + (Phi - 1)^2 + (Phi - 1)^3 + ... + (Phi - 1)^n + ...) = (Phi - 1) / (1 - (Phi - 1)) = Phi

And finally we have

golden spiral length = (Pi / 2) * Phi ~ 2.5416018461576299079047545066211

ta daaa!

I hope you can find it funny and clear. My English is not good enough

Ajit's initial equation was correct
by: B

The r1 is the radius of largest arc, r2 is the radius of the second largest, etc., then the radius of any arc in the sequence is

rn = (.6180339....)^(n-1)

The first radius, r1 = 1
The second radius, r2 = .6180339...

Circumference = 2*pi*r
Circumference of one quarter of a circle (quarter circles are what form the golden spiral) = (2*pi*r)/4 = (pi/2)*r

If a1 is the largest arc, a2 is the second largest, then the length of any arc in the sequence is

an = (pi/2)*(.6180339....)^(n-1)

The sum of a1 + a2 .... + an, as n approaches infinity, = 4.11239817295
length of golden spiral
by: Ajit

I stand corrected in the calculation submitted. The length will, in fact, be half of 4.1120...i.e. 2.05602 for if the side of the square is 1 unit then the radius = 1/2 and thus length of spiral = 2*Pi*r/4(1-k) = Pi/4(1-k)=2.05602 approxly.
by: Jill

Hi Ajit

I must confess to not being a mathematician. From a practical, artist's point of view the 1:1.618 works fine. Have you tried to construct a rectangle or spiral using the proportions mentioned? The golden mean is a well tested theory but you may well be right in your calculations.

Any other maths whizzes like to join in this discussion?

Thanks for taking the time to contribute.


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buying art work

by mitford
(vic aust )

I have looked at art work on this site and can't find out how to buy and for what price.


by: Anonymous

Without a basic price guide what is one to guesstimate for costs. My clients would not want to deal with such unknowns.

price range for 8 X 10

price range for 11 X 17 or 24 X 36?

Now to buy artwork
by: Jill

Dear Mitford

Which artist or artworks are you interested in purchasing?

There are a number of contact forms on the site, including one on the left in the navigation bar, so the best thing is to fill in one of those forms and I shall pass your enquiry on immediately to the artist concerned if I can't answer your query myself.

Not all of the artwork displayed here is for sale
but most artists are making new work all the time so we can send you up-to-the minute information if you tell us the sort of work that you are looking for and a rough idea of your price range.

Hope that helps.


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Millinery feathers

by Emma

Hi I live near Townsville and have opened an on-line boutique selling second hand and vintage designer fashion. I'm looking into millinery but a lot of feathers aren't up to scratch and I would like to create something a little more interesting.

So I would like to look into silk feathers, developing and painting my own unique feathers for hats and fascinators etc. if you already know someone who does this that would be fantastic! But if not...where do I start?

Is it best I find an artist to work with or learn the art of silk painting my self? Is there anyone in the Townsville area I could contact? Any information would be wonderful.


feather supplier
by: Debbie

I am just getting into millinery and looking for a reliable supplier for feathers, veiling etc. I'm kinda lost on the internet. Any ideas would be appreciated.
about colour feathers
by: Wendy White

If you need a couple of sites to check out on feather dyeing try www.flyangleronline.com or ginabellousdolls.com. Both of these will show you how to dye feathers in the microwave.

You need to use hot water dyes either Jacquard acid dyes or Rit which is now available in Spotlight. Both of these work really well.You have to break down the natural oils which are in the feathers.

If you are using off the ground eg chook feathers it pays to put them into a freeze for a couple of week just bag and tag. This will kill any mites. Also silver fish love fresh feathers I mean ones that have not been dyed.

For some other ideas you can sticky tape and spray with spray paint. I just use the ones from Bunnings or there are others like the design master range.

You can also acid your feathers by dropping them into a bath of good bleach but don't leave them there too long as you will have a stick left(ostrich feather come up the best).

When you have the right effect you need to run them under cold water to get the bleach out and stop it working.

I am a fulltime milliner in Rockhampton and have been doing a lot of my own dyeing, aciding and feather work for the past 6 years. Also if your feathers are not the best you might need to find yourself a different supplier. Also nothing a bit of cutting, trimming and manipulation will not fix. just think outside the box. sometimes you need the whole chook to get a look.

There are some great suppliers on ebay for feathers.

Yours, Wendy White Bush Buddies
Happy hatting
dyeing feathers
by: Anonymous

There is a ton of info on how to dye feathers on the internet.
Look for info from folks who tie fishing flies. They are experts at getting consistent color and their directions are precise.
Good luck!
experimenting with dyes and feathers
by: Jill

Emma, sorry to say that my experiment with dyeing feathers was not successful. I used my normal fibre reactive dyes but didn't take into consideration the wax / oil that is on the feathers and this, of course, resisted the water-based dye.

Maybe people who dye feathers successfully use something like hair dyes?

Sorry I couldn't help. Have you looked at the commercial dyed feathers on sale via the internet? They mostly look very glamorous.

Good luck - let us know how you get on and how your business is going?

Great idea!
by: Jill

Hi Emma

That's a great idea! I am sure that feathers will add to the interest of your vintage clothing.

However I think that it would be so difficult to make feathers out of silk and really, Nature does a pretty good job.

I googled 'dyed feathers' and found a couple of really good sites that sell a variety of feathers from quite large birds such as ostriches to much smaller ones. I think that the fibre reactive dyes that I use on silk would work on feathers. I shall see if I can find some on the beach and try it out for you.

Maybe you could get feathers from a bird or wildlife park - imagine how stunning lorikeet feathers would be!

Your idea of using dyed and painted silk in your business sounds excellent. Painting with dyes is great fun and I expect that your local arts group would have a teacher available.

I plan to write a small e-book about silk painting so that might interest you when it is done. So check out this site in a couple of months - I shall let people know via the newsletter too, so maybe fill in the little form in the nav bar if you would like to receive that.

Good luck with it all!

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Art Classes

by Diane Neeld
(Palm Cove, Queensland)

I would like to know where, in the Cairns area, are various Art Courses held?


Art education
by: Anonymous

Dear Diane

Please see this page - https://www.art-in-tropical-australia.com/your-art-classes.html#INV

Of course there are also classes at TAFE and JCU but maybe you mean hobby-type ones rather than certificate or degree ones?

Cairns Regional Gallery regularly holds workshops in conjunction with exhibitions as well as a children's programme. Good luck!


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