The computer told me the post was too long and to shorten it to 10,000 characters, so I cut and copied the last part of it into this next post which deals exclusively with the COLOUR making decision:
C. Also, tell your wife that bright colours look nice, but they're not very resistant to UV light. Tell her she'll have far less fading if she were to choose an "inorganic
" colour, like mustard yellow, reddish brown, chocolate brown, raw umber, white or black. That's cuz all these colours are made by pulverizing coloured rocks into a fine powder and using that powder to tint the paint
. Rocks are good at being opaque, but they're even better at being old. Anything that's 300 million years old has to be extremely chemically stable or it would have decomposed by now. That extreme chemical stability means that rocks don't fade from exposure to UV light from the Sun like synthetic chemicals do (which is what the pigments
in red, blue, green, yellow, orange, purple and magenta colourants are made from).
NOW, that last paragraph is ALMOST true. For the past dozen or so centuries artists have been making their pigments
from pulverizing coloured rocks like ochre, umber, sienna (which is actually named after a village that still exists in Italy where the surrounding rocks and soil are a mustard yellow colour) and charcoal (which ain't a rock). Nowadays, the inorganic
colourants used in the paint
tinting machine are the same chemicals found in coloured rocks (iron oxides with impurities that make them change from a mustard yellow to a burnt orange to a rust colour to a chocolate brown to very dark brown (called "umber")), but the fact that the iron oxide and added impurities in them is man made and a synthetical product doesn't change it's characteristics. It just makes the supply of such pigments
more reliable (cus they don't have to come from politically unstable areas) and of higher colour consistancy and of more uniform particle size (so as not to affect the gloss of the paint
). However, if someone asks me why synthetic iron oxide isn't affected by UV light from the Sun, I can only answer "I don't know" (cuz I don't). But, when I explain to people that the exact same chemical is found in rocks that are 300 million years old, and therefore extremely chemically stable, they intuitively seem to understand that that chemical stability would manifest itself in less fading when exposed to Sunlight. And, of course, if rocks faded from Sunlight, they'd all be faded white as a ghost by now. The fact that the little village of Sienna is still as mustard yellow as ever is proof of the extreme chemical stability of these iron oxide compounds.
D. Every kid that has ever played "hide and seek" outdoors knows that most rocks are opaque. Most people, however, don't know that the pigments
used in "organic" colour (which are the colourwheel colours, or red, yellow, blue, green, orange, purple, and so on) look like tiny lumps of coloured plastic (with varying degrees of transparency, depending on the kind of pigment) under a microscope. Inorganic pigments
look just like coloured rocks under a microscope. As a result, you generally get better hide with "inorganic pigments
" (pronounced "pulverized rocks") than you do with organic pigments
, because all of the iron oxides are opaque, but many of the organic pigments
are fairly transparent. (That last statement assumes all other factors are equal.) Also, they can add more coloured pigments
to an oil based paint
than they can to a latex paint
, so a pretinted oil based paint
will normally hide better than a pretinted latex paint
of the same colour.
at the point of sale in a paint
tinting machine is a whole nuther kettle of fish. The carrier fluid in the different colourants is glycerine (so that both oil and latex paint
s can be tinted with the same colourants) and glycerine affects film formation in latex paint
s completely differently than that of oil based paint
s. So, latex paint
s are more restricted on how much you can tint them at the point of sale. If you add the dry pigment right at the paint
factory, you can add more dry pigment of any colour to a can of alkyd paint
than you can a can of latex paint
before you have problems.)
Sun Chemical is the biggest name in organic pigments used to make colourants for tinting paint:
Unfortunately, Sun Chemical's web site isn't really set up to help DIY'ers like us learn more about organic pigments.