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Blue shift (why does my white turn blue)

Discussion in 'Colour Theory' started by haasje dutchairbrush, Apr 30, 2015.


  1. haasje dutchairbrush

    haasje dutchairbrush Air-Valve Autobot! Very Likeable!

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    I got asked this question by mail and as I had to wite it down anyway I thought it might be a good idea to post it here also as it does seem to be a reoccuring question :p


    Why does my white turn blue when airbrushed on another color?


    First off, the technical explenation: http://www.ing.unibs.it/~zkovacs/color/TiO2_E.htm

    The above link is the scientific explenation for those who find it interesting (I don't think I got half off it :p) what follows is the short "for dumies " version in regard to airbrushing :D

    When using white on any other color, but most noticably on black one will see that the white gets a blue hue, this is known as "blue shift". Most people starting out with airbrushing and without a background in art will be surprised by this and wonder what they are doing wrong.

    Nothing is going wrong here, this is just how it works (see the lengthy technical explenation) and it's something an airbrusher has to learn to live with/work with. The blue shift is often seen as something anoying but once one accepts it as just a fact it can also be used to ones advantage.


    How to prevent/work around blue shift


    -The easiest method is just not to use white. This is one of the reasons we see so much erasing and scratching going on in airbrushing. To avoid blue shift the white of the paper is used.

    -Work from light to dark. The problem here will be that mistakes will be tough to correct (especialy when working transparant)

    -Orange being the opposite color of blue can negate the color blue. Adding a minute amount of orange to white can thus neutralise the blue shift (this sounds easy but it takes some practice as too much orange and your white is no longer white and not enough and you'll still have a blue shift)

    -A "dirty trick" when using whites in parts and thus getting a blue shift is to fog over the entire piece with a very reduced white. This will cause a blue shift on the entire picture making it not stand out anymore. If using this trick (I use it only when doing rush jobs) it's advisable to do it before going in with the real darks (shadows)


    Using blue shift to ones advantage

    As said one won't get around blue shift, it's here to stay :p. Knowing this it can also be used to ones advantage though.

    When used propperly blue shift can create the illusion of wetness or translucency.

    -It can be used as a "white wash" where an area is fogged in with a reduced white. This will merge/blend the colors beneath it. This is a good effect to use on skintone or eyes as it will give it a translucent effect.

    -When doing a "wet" texture (reptile skin for instance) using white to do highlights will have the blue shift create the illusion of it being wet.


    As said above this is the short "for dummies" version there is probably a lot more to say about it but I think this covers the most important stuff in regards to airbrushing and blue shift :)
  2. Mr.Micron

    Mr.Micron Royal pain in the air hose Staff Member Admin Very Likeable!

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    Very helpful as always and great write up
  3. Boltcase

    Boltcase Guest

    Thx Haasje...well said :)
  4. basepaint

    basepaint Air-Valve Autobot! Very Likeable!

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  5. beanpoleuk

    beanpoleuk Love this place! Artist of the Month! Forum Supporter Very Likeable!

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    Very useful, thanks for taking the time to write this up, I do have a question though. During my recent experiments with t shirts I dont seem to get blue shift when spraying over any of the colours underneath. I assumed it is because the white us going down quite thick compared with the light layers on paper ?
    haasje dutchairbrush likes this.
  6. matty171

    matty171 Air-Valve Autobot!

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    Thanks haasje i love your for dummies explanations as i can take in to much info at once lol
  7. boneman65

    boneman65 Guest

    Thanks for the headache @haasje dutchairbrush lol... i tried to read the tech before my coffee.....big mistake....lol....thanks for the info
    haasje dutchairbrush likes this.
  8. haasje dutchairbrush

    haasje dutchairbrush Air-Valve Autobot! Very Likeable!

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    Ever since I encountered this myself for he 1st time I have tried to understand the technical side of it (although by now I resigned myself to the fact I probably will never fully understand this unless I start to studdy chemistry/physiscs :)). The link I posted seems to provide the most elaborate explenation but there are a lot off different ones ""floating around" on the net (and not all giving the same explenation :p)

    To be honest I don't get the technical side of this 100% myself, thats why I didn't do a summary of the article I posted the link to and stuck to the for "dummies variant" as I by now do know how blue shift applies to airbrushing just due to experience :D.

    I never had blue shift when I worked with oil paints so t-shirts might be the same. As far as I understand (and I might be wrong here !) it, like you said has something to do with the thickness of the paint/layer applied. Color is light we percieve and white means no color is filtered out and everything is reflected back.

    I once (can't find the link) saw a drawing of airbrush paint being resembled by little dots. By the nature of airbrush (overspray) those little dots won't cover everyting having stuff beneath it "shine through". As we are working with light the parts not 100% covered with the dots will not reflect light 100% (as only white dots do that) resuting in the shift.

    Like I said I could be very wrong here but to me it sounds plausible as when I use masking on a bike to do a pinstripe in white and realy flood fill it I don't get a blue shift but just a nice white line (if I did my masking properly :D).

    It might also have to do (but this is just a gues) with color bias: http://www.airbrushforum.org/threads/color-bias-why-does-yellow-and-blue-make-brown-not-green.11524/
    WhiteKnight likes this.

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