Skip to main content
S
sPretzel
Inspiring
April 25, 2018
質問

Multiply blending mode

  • April 25, 2018
  • 返信数 4.
  • 16403 ビュー

Hello,

I thought I understood how this worked but apparently I don't.

Illustrator's user guide states: How to edit artwork using transparency and blending modes in Illustrator

Multiply

Multiplies the base color by the blend color. The resulting color is always a darker color. Multiplying any color with black produces black. Multiplying any color with white leaves the color unchanged. The effect is similar to drawing on the page with multiple magic markers.

In CMYK space, if I have an object filled with 30 0 0 0 set to multiply on top of another object filled with 30 0 0 30, I get for the overlap 51 0 0 30 !! I am no longer sure what I was expecting but it would have probably been 30 0 0 30. My question is:

1- how does "Multiplies the base color by the blend color" actually operate on the numbers to get to 51 0 0 30?

I had to check this in Photoshop to get the resulting value. So my second question is:

2- how can I check the resulting colour value directly in Illustrator?

This is for CS4.

Thanks.

    このトピックへの返信は締め切られました。

    返信数 4

    angie_taylor
    angie_taylor
    Legend
    April 26, 2018

    Also, I seem to remember that with Multiply mode the top layer’s numbers are inverted before being multiplied with the bottom number?

    c.pfaffenbichler
    Community Expert
    c.pfaffenbichlerCommunity Expert
    Community Expert
    April 26, 2018

    Both numbers are translated to a value between 0 and 1 with 0 being »dark« and 1 being »light«.

    So for 30% on 30% that would be (1 - 0,7 x 0,7) x 100.

      ceyhun_akgun
      ceyhun_akgun
      Legend
      April 26, 2018

      This is a very difficult issue to find with normal values. If you interpret your color and your work because of the ICC Profile you are using, a different value arises. When you multiply, the color values ​​in the blend vary. So, the upper color and the lower color do not mix at 100%. I'm having trouble with Layer Mode. I use manual methods while straightening the blend colors in pre-press preparation for packaging.

      "This is your choice for a darkening effect. It multiplies the blend layer’s colour channel values with those of the base layer. Black in either layer gives black; white leaves the other layer’s colour unchanged. Lighter greys will give softer shadows, while darker greys will give deeper shadows. Why? Well, black has a value of 0, and white has a value of 1, and all other multiplied values are divided by 255. “Class, get your calculators out!”

      Graphic Designer Educator / PrePress Consultant
      c.pfaffenbichler
      Community Expert
      c.pfaffenbichlerCommunity Expert
      Community Expert
      April 26, 2018
      In CMYK space, if I have an object filled with 30 0 0 0 set to multiply on top of another object filled with 30 0 0 30, I get for the overlap 51 0 0 30 !! I am no longer sure what I was expecting but it would have probably been 30 0 0 30.

      You might be confusing the setting »Overprint« and the Blend Mode »Multiply«.

      This is not the actual math but it might help illustrate nonetheless:

      The base Layer’s 30% are the base, you multiplying 30% onto it means that

      • 30% of 70% (the difference between the base’s 30% and 100%) get added to the 30%. 

      (0,3 x 70) + 30 = 51

      Ton Frederiks
      Community Expert
      Ton FrederiksCommunity Expert
      Community Expert
      April 25, 2018

      If you are interested in how Blend modes work, see the PDF Blend Modes Addendum

      Blend modes addendum

      It is not simple (at least for me) and it seems to convert the colors (RGB or CMYK) to some  intermediate HSL representation.

      Doug A Roberts
      Community Expert
      Doug A RobertsCommunity Expert
      Community Expert
      April 25, 2018

      I think that just applies to the Hue, Saturation, Colour, luminosity modes Ton. the other blend modes contain the usual formulas I've seen before.

      the key bit here is this:

      "The above formulas apply to RGB spaces. Blending in CMYK spaces (including

      both DeviceCMYK and ICCBased calibrated CMYK spaces) is handled in the following

      way:

      • The C, M, and Y components are converted to their complementary R, G, and B

      components in the usual way. The formulas above are applied to the RGB color

      values. The results are converted back to C, M, and Y.

      • For the K component, the result is the K component of Cb for the Hue, Saturation,

      and Color blend modes; it is the K component of Cs for the Luminosity

      blend mode."

      So it does do an RGB conversion.

      Doug A Roberts
      Community Expert
      Doug A RobertsCommunity Expert
      Community Expert
      April 25, 2018

      i can tell you how it works in RGB.

      each blending mode is an equation with the colour value of each channel converted to a figure between zero and 1 (zero is 0, 1 is 255)

      so a yellow value of 100 is input as 0.39...

      multiply, for example, is (background colour x foreground colour).

      because both values will be less than 1, you end up with a lower number than you started with. thus, the colour value will be darker (closer to zero).

      this doesn't work with the CMYK values, because they're percentages with the darkest value at 100%. I'm not sure, but i suspect the blend mode is actually doing the maths on an RGB conversion of the CMYK colour.

      Doug A Roberts
      Community Expert
      Doug A RobertsCommunity Expert
      Community Expert
      April 25, 2018

      either that, or there's some internal formula for the value of overprinting inks (which is the real-world analogue of Multiply in CMYK).

      c.pfaffenbichler
      Community Expert
      c.pfaffenbichlerCommunity Expert
      Community Expert
      April 26, 2018
      either that, or there's some internal formula for the value of overprinting inks (which is the real-world analogue of Multiply in CMYK).

      Equating »Multiple« with »Overprint« would be a mistake; in »Overprint« any Channel of the overprinting object that contains non-0 values takes precedence, those that contain 0 are ignored.

      An object of the CMYK color 1/1/1/1 set to overprint on any other CMYK background (like 0/100/100/0) would result in 1/1/1/1.

      契約条件Accessibility statement
      Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices