I'm creating a letter and want to include a highlighted section, I'm trying to find the best CMYK blend that represents that when printed.
I would contend that this is difficult to answer definitively.
If you're talking a four-color process, a straight 100% 'Y' would probably be your best bet. However, highlighters tend to have a neon glow about them, which can't be achieved in CMYK. You'd need a special process color for that.
Get your hands on the highlighter you want to emulate, draw on paper, and use either a swatchbook or printed samples from your local printer to experiment. That's going to be better than anyone here giving you an answer.
If you want to include a highlighted section and you want realism though, the best way to go about that is to study what physical highlights look like in terms of the shape of the highlighted block. Computerized facsimiles look fake because they're perfect rectangles. If you give it a bit of a shake, and one edge is a bit rough, and the thickness isn't uniform, that might go a long way in making a highlight look real.
To add on to Brendan's answer, the "Neon" quality of "Neon Yellow" can be achieved in CMYK, but that's not all a highlighter is.
A physical highlighter doesn't contain the pure yellow we expect from printers and monitors, but a slightly more watered-down version, so step one would be to use, say, 75%-80% yellow to start with.
Next, to achieve that brightness, I look to studies pointing out that the brightest color humans see is on the yellow side of green , which is that same color you see on newer emergency vehicles:
Using these two facts (Highlighters aren't the pure yellow we get from printers and monitors + The neon effect comes from being closer to green), we get the following color:
- CMYK: 2.5%, 0%, 80%, 0%
- RGB: 249, 255, 51 (#F9FF33)
- HSL: 62°, 100%, 59.8%
- Closest PMS: 101 C
Feel free to add more cyan and subtract more yellow as needed!
Highlighters tend to use fluorescent pigments/dyes to give you the bright colors (AKA, 'higlighted' colors). As such, there is no CMYK combination to emulate them as CMYK doesn't include any colors that would be considered part of the 'fluorescent' color space.
If you want a true match, then you need to use a spot color. Pantone has a whole line of fluorescent colors.
If you're stuck with CMYK, I'd suggest 100% Y as a start.
I use 100%Y at 60% or 70% opacity and set the blend mode to
I can't say this is "right" or "correct", merely what I prefer. My goal is to provide the appearance of a basic highlighter. I've never been concerned with absolute color matching. Primarily because colors can and do vary by manufacturer.
It may seem like I pulled those number out of a hat. I did not. Note that I did actually test this with commercially printed pieces over a several month period. I have adjusted the color percentage to determine what looks best to me and according to what pieces had higher returns.
- I tried a 100%yellow/20% magenta set to multiply (too overpowering)
- 100% yellow 100% opacity set to Multiply (still too vibrant)
- 100% yellow 80% opacity set to Multiply (good and needed for pieces with darker stock or backgrounds)
- 100% yellow 60% opacity set Multiply works best for pieces with white or light colored backgrounds in my opinion.
Multiply is used to allow content underneath to build rather than be covered. Overprinting will also work, provided the piece is not too "yellow" in nature.
For pieces with an overall yellow tone, I tend to shift to a lime green color for the highlighter (40C/50Y) or 100% magenta rather than yellow. My primary concern is to make the highlighting always appear as an afterthought and not actually part of the design itself.
The most usual approach is a 70-85% Y. If you use a blend mode other than (not recommended, a simple screen is best), be sure to place the highlight under the text, so it doesn't get rasterized if the file goes through a PostScript RIP the output is flattened. You should in any case set Black to overprint in Illustrator or InDesign when you're working with background colors or simulated highlighter.
If you're using InDesign, the usual technique is to simulate a highlight by using an Underline set to your highlight color. Make it slightly taller than the text. Underlines and paragraph rules are always below the text in the stacking order, so you never have to be concerned about it printing on top of the text.