Lab lighting

Lynn Campbell <lynn.campbell [at] ccc__govt__nz> writes

>I have a question on the use of daylight for retouching of oil
>paintings.

We have had a lot of discussions and drawn on a varied experience
with regard to windows for retouching paintings and other items.  My
advice is to have a series of tall windows- preferably right up to
ceiling height- and about 2 meters wide evenly spaced and have at
least two for each inpainting station. These should be as close to
south facing in the southern hemisphere as possible, and they should
have vertical blinds to allow you to control the light as you wish.
There is no advantage to having them down to floor level- about 1
meter off the floor is fine.  Radiant heat will be a problem if
direct sunlight comes in and can be surprisingly dangerous- black
paint heats up real fast.  You want indirect light to come from
behind you and to be able to vary the angle of the painting to
achieve the best result, which will vary and change.

Be aware of the Kruithof curve and that in order to get decent
results, you need at least 600 lux on the surface of the paintings.
I have in the deep dark past done a lot of retouching with
artificial light and I recommend avoiding it as an absolute last
resort- if you can get good sunlight.  But remember that sunlight is
changing colour and intensity all the time so keep those lux up.

The other big thing is the colour of the room.  John Payne, our
Senior Conservator of Paintings, painted his entire lab a mid grey
(which we naturally call Payne's Grey).  He went to the extent of
having all the pipes, the ceiling, the furniture-everything- in
grey.  I was initially skeptical- but it has been an absolute
revelation.  In the past year two incredibly long and delicate
retouching jobs were carried out in that lab and I'm convinced they
never would have been completed without the repainting of the space.
John can give you an exact specification for the paint.  You really
will just have to take my word on this- just do it!

Regarding the fish bowl phenomenon, it has been suggested to me over
the years that conservators make great show pieces and wouldn't it
be wonderful if their studios had glass walls so members of the
public could watch their every little movement?  My first answer to
this is yes, like other staff members, we are all too pleased to do
our part and when the director's office and the board room have
glass walls, I will not only accept them, I will insist on them.
While, naturally, agreeing that conservators really do have a lot to
offer, I've found I'm more successful- not to mention comfortable-
in a tux with a glass of nice bubbly explaining to dinner guests
around a table what we do and why it is important- than I am likely
to be being observed from afar (I hope) sitting at my desk talking
on the telephone to an artist or curator or writing an e-mail on the
computer.  I also believe people need privacy in order to
concentrate and some of what we do requires a great deal of
concentration.

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                  Conservation DistList Instance 13:6
                  Distributed: Wednesday, July 7, 1999
                        Message Id: cdl-13-6-006
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