Smudged Lines: Why They Happen & How To Prevent Them

Sometimes we want smudged lines when we color – especially when blending.

However, no one likes it when the printed outlines on a coloring page are the smudged lines. I briefly talked about this problem in this post about printing coloring pages at home. However, several of my readers (thanks especially to Ellen!) have told me they are having this problem, not only with printables but with coloring books as well.

Smudged Lines
Examples of Smudged Outlines

Why does this happen? And is there anything you can do to stop the smudging?

Smudging can be a result of one – or a combination of – three factors:

  • The paper used for printing
  • The ink used to print the design
  • The medium you are using to color: marker, pen or pencil

The Paper
Don’t underestimate paper. Good paper makes a HUGE difference in coloring. More than you’d expect.

Some coloring books use relatively rough paper, one that has some “tooth.” Toothy paper can be excellent for pressure shading, layering or blending colors. But when you press down while coloring over the lines (I mean, who really colors inside the lines?!), the paper fibers with the ink can be pushed away from the original outline giving the appearance of smudging. This is especially true when you are using colored pencils. Combine pressure with a marker, especially a water-based one that can “pull” the paper’s fibers, and the crispness of the outline will be gone, too.

When buying coloring books, look for smoother paper. Usually, but not always, that means avoiding the cheapest ones. You may have noticed that I do now focus on paper quality as part of my coloring book reviews, like this one.

When you print at home with an ink-jet printer, using a higher quality paper will lessen the likelihood that the outlines will spread. If you don’t want to display or keep your coloring for a long time, or use advanced techniques like burnishing or blending, plain old multi-purpose copy paper like Staples plain paper will be just fine. A step-up in quality is this paper from Neenah.

The Ink/Printing
Most coloring books are made using a digital printing process that is similar to making a laser photocopy: the image is almost tattooed into the paper. Some coloring books are made using more traditional printing processes that use solvent-based ink. In both cases, the ink generally won’t budge. So under normal circumstances using decent paper, you shouldn’t suffer any smudging with any medium – markers, pencils or pens.

However, even if the ink is permanent and the paper decent, some coloring book publishers do use lower quality images: if you look closely you can even see that the lines are not solid but lots of little dots called pixelation.

Smudged Lined
Click to Open Detail in New Tab

If you color into the line, the color will fill in the spaces between the dots and the line will appear smudged. For this same reason, be careful when choosing images from the internet to print at home for coloring. To save space and make loading pages fast, web images are less than 100 dots per inch; if you save an image like this on your computer and then use an application to enlarge it to fill a regular-sized 8-1/2” x 11” page, the lines won’t be sharp at all.

Take a good look at the images when you are buying a coloring book – either online or in a store. Of course, this is much easier in a physical store, but even online sites including Amazon may have sample pages (i.e. with the “Look Inside” feature or even images provided by the publisher).

As for home printables, inkjet printers, such as the one I use, are more challenging because the ink is water-based – and wet. To avoid smudging and smearing the printable’s lines, wait at least 30 minutes after you print it before you start to color, and keep your hands dry and free from creams or lotions. And remember that water-based markers like Rose Art or Tombows will make inkjet ink bleed to some extent, even if you wait for 24 hours for the ink to dry. And if you use colored pencils, use a light hand when you color on or over the line.

The Medium
If you are concerned about smudging because of the paper quality or pixelation, your safest bet is to stick to alcohol-based markers like Prismacolors or BIC Markits. You will likely have bleeding, of course, but even ink-jet printed lines (that have dried completely) won’t budge.

Try to stay away from water-based markers if you print at home using an ink-jet printer. As mentioned above, I have found that even if I wait 24 hours, there can still be smudging as the water in the marker dilutes the water in the image’s ink.

If your problem is pixelation alone, all markers and pencils will make the lines look smudgy. One thing I have done which seems to work is, after finishing my coloring, I use a fine black marker to trace over all the lines I want to be sharp and clear.

Final note: I have not tried this myself, but I have heard that artists fixative may work for “stabilizing” ink-jet printables. Simply spray a very light coat over the image, let it dry completely and then color. Apparently the fixative seals the image’s lines so they won’t smudge. I have some fixative on order and will let you know how it works when it arrives.

Have you had problems with smudged lines?  What do you do to prevent or correct them? Let us know in the comments below.

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5 thoughts on “Smudged Lines: Why They Happen & How To Prevent Them”

  1. Thanks. This totally explains what was happening. From the lower quality paper and books. Also, the pencil I was using. As expected when coloring with my prismacolor with a good book. All looks great.

  2. The fixative will fill in the tooth of the paper and may make blending/shading difficult.

    1. adultcoloring101 says:

      I never thought of that – I’ll watch for it when I try it…

    2. Not if you use a WORKABLE (aka MATTE) FIXATIVE. This type of fixative is designed to work over. It’s a matter of knowing your supplies and how to use them

  3. A “workable fixative” will not fill in the tooth like a “final fixative” does. They are commonly used between layers of color. I’m excited to hear how this works for printed coloring book pages. There’s nothing worse than trying to color a page with tiny details…especially with light colors and yellows!

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