

The Magical Tech Behind Paper For iPad's Color-Mixing - julianwa
http://www.fastcompany.com/3002676/magical-tech-behind-paper-ipads-color-mixing-perfection

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gmaslov
I was disappointed to read that they gave up the principled modeling approach
(the 80-year old German paper mentioned early on in the article) and instead
collected 100 data points that "looked good" and interpolated somehow.

The article says that the Kubelka-Munk model achieved color mixing that was
"too realistic" and therefore difficult to use for the purpose of creating a
distinctive brand palette. What this tells me is that they weren't looking for
a model of how colors mix together, but a model of what colors look good
together.

> "We know red and yellow should yield orange, or that red and blue should
> make purple--but there isn't any way to arrive at these colors no matter
> what color-space you use."

Well, that's clearly not true. In the HSL color wheel [1], orange is halfway
between red and yellow, and purple is halfway between red and blue. Should
have picked a better example.

[1] <http://www.workwithcolor.com/hsl-color-picker-01.htm>

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jules
Look at it another way. What is the goal of their product? A person should be
able to sit down, and draw something. That person has a model in his head of
what the drawing should look like. He picks and mixes colors to achieve this
according to his intuition. So the goal of the program is to match human
intuition, _not_ to match reality. Why would real world paint be the optimal
painting tool? The best way to match human intuition is to base the behavior
of the program on data collected from human intuition.

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andrewingram
I'm blown away by the effort put into a single feature, a feature which isn't
even unlocked in the basic install of the app. Seriously impressive dedication
to getting something right.

~~~
charlesmchen
We're lucky enough to have founders that are designers and engineers, and we
have a design-driven process and a commitment to high quality standards. It's
a pleasure to know you'll get the chance to get things right.

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rsl7
Style over substance.

Mixing colors would be a neat addition if the rest of the app was geared
toward actual creative work. Drawing is laggy, there's no zoom, the UI
enforces landscape mode, you can't select your own drawing order or see more
than one drawing at a time with their fancy pants book page flip animation.

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gstar
The URL in the screenshot still works, you can play with it in the browser:

[http://dl.dropbox.com/u/6432940/paper/mixingWell/24/index.ht...](http://dl.dropbox.com/u/6432940/paper/mixingWell/24/index.html)

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AceJohnny2
no longer.

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stevenwei
Make no mistake, this level of attention to detail is why this app has
remained consistently in the top charts since its release.

~~~
alayne
It's on the charts because it's "free". The overall rating is only 4/5 stars
on itunes. They use the annoying model of making you buy tools like color as
in app purchases.

Notability, which has some similarities, sells for 0.99 without in app
purchase nonsense and is rated higher.

~~~
glhaynes
I don't get the hate for in-app purchases of this kind. It's just like the
shareware model that used to be popular: lots of people get absolutely free
usage/enjoyment out of the base product and then, those who specifically want
more, can pay—in this case a very small fee—for it. One constantly hears
people clamoring for more choice, for example, to pay for just the cable
channels they want. So what makes this model "annoying nonsense"?

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kenperkins
I think because some class of people wonder if a $5 app would better perform.
I think it's hard for 53 to succeed that way however, because you have a
finite number of users.

By making features an in-app purchase, they effectively monetize users going
from version 1 to version 2, and so on. If you used the up-front payment
model, new versions of the app would have to be a different app to continually
monetize it, which would have a number of it's own problems.

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leephillips
This quote from the article:

“Compare red nail polish to red ink: both are red, but the nail polish will be
visible on black paper because it reflects light. The ink won’t be, because it
absorbs light.”

doesn't seem right to me, but I'm not an expert. The ink doesn't reflect
light? If you put a drop of red ink on a sheet of glass, it won't look red?
Isn't the difference because the ink will soak in to the paper while the
polish will sit on top of it?

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maggit
The nail polish is opaque, which means it reflects or absorbs light that hits
it. Red nail polish reflects red light and absorbs the rest. Shine white light
_on_ it, and it will look red.

Ink is transparent; It lets through or absorbs light that hits it. Red ink
lets though red light and absorbs the rest. Shine white light _through_ it,
and it will look red.

Shining white light _on_ a black piece of paper with red ink on it will look
black. What light is not absorbed by the ink is absorbed instead by the paper.

Of course red ink reflects light, as you say, but that is just because of
reality. It is not essential to its function. If it were possible to make a
100% non-reflective ink, it would work perfectly well.

I hope this clears it up :)

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leephillips
It does. Thanks to you and the other excellent replies, I now finally
understand how ink works. Apparently it's a filter, and we see the light after
it has been twice filtered by the ink, down through the ink into the paper and
reflected from the paper back up through the ink to our eyes. In contrast to
paint or polish, which reflects from its surface.

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mitjak
I'm curious as to why the article felt it necessary to highlight multiple
times that the German scientists are "dead"…

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dspillett
They're _not_ dead. They're pinin' for the fjords.

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achille
The examples shown are neat and the screenshots shown are usable on your ipad:

[http://dl.dropbox.com/u/6432940/paper/mixingWell/4/index.htm...](http://dl.dropbox.com/u/6432940/paper/mixingWell/4/index.html)

[http://dl.dropbox.com/u/6432940/paper/mixingWell/22/index.ht...](http://dl.dropbox.com/u/6432940/paper/mixingWell/22/index.html)

[http://dl.dropbox.com/u/6432940/paper/mixingWell/24/index.ht...](http://dl.dropbox.com/u/6432940/paper/mixingWell/24/index.html)

Interesting they use Processing.JS and CoffeeScript.

This is an interesting technical post, but why is it being hosted on
fastcompany.com. This belongs on their blog.

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charlesmchen
These prototypes were developed by designer Andrew Allen
<https://twitter.com/asallen> working with prototyping engineer Amit Pitaru
<https://twitter.com/pitaru>

If you'd like to discuss our approach to color blending, I can be reached at
<https://twitter.com/cmchen>

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achille
Just curious, why'd you take down the prototypes? I'm assuming the actual app
doesn't share any of that source.

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0x0
I wonder if CMYK would be appropriate? The article didn't mention anything
about it (even though it talks about how they tried a bunch of other color
spaces by name)

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aw3c2
CMYK is an subtractive color model, it is not very understandable and
definitely not intuitive for human color perception. HSL is much better for
that. It all is not too revelant in the end result I think because those are
just models and their software exposes certain aspects of colors.

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sp332
Mixing pigments (ink or paint) can be done in CMYK because it _is_ a
subtractive process. It would have been realistic and something that anyone
who has played with finger paints or crayons has experienced. (Although I
agree that it's not very relevant to the end result, it would have been nice
to see it in the discussion.)

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aw3c2
Geez, I feel stupid about that comment now. Was too much in the "monitors are
RGB, CYMK is only for print" but of course, when mixing colors it might be
good indeed.

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namank
I love that you discarded all solutions that didn't meet your criteria.

It's the only way to make great things.

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aw3c2
I find that hard to read, might be all the breathless adjectives? It does seem
quite interesting though. They used some 80 year old paper on color
blending/mixing. I wonder if they patented their derivative implementation.

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kmfrk
Another way to get an appreciation of the skill of the creators is to watch
their amazing promotional videos.

<https://vimeo.com/fiftythree/videos>

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t_hozumi
This article really made me rethink importance of investing a great deal of
energy in core problem. More importantly, we hardly notice that there is such
a deep problem we should solve.

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tammer
Anyone know any desktop or web apps with similar functionality? I don't have
any iThings and am bored with conventional color pickers.

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archagon
Corel Painter has paint mixing, but I don't know how it compares to Paper's
approach.

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jcl
ArtRage also has a paint layering/mixing model, although I'm guessing it's
using neither Kubelka-Munk nor Paper's survey-based approach.

<http://www.artrage.com/artrage-studio-features.html>

