GIMP / Threadless Tutorial

Art, Uncategorized

If you are designing / drawing for print on demand, you may have struggled [as I have] to find GIMP tutorials… One of the most frustrating aspects of searching for directions was time wasted on lengthy introductions to not-so helpful tips which focused largely on anything other than GIMP — so, let’s dive right into your work, shall we?

What you’ll need:

  • Your artwork
  • Scanner – I use the Notebloc app on my Android smartphone. I’ve used several scanner apps and this is the best I’ve found to date. I’ve also found it easiest to scan in my local library in front of large windows that let in plenty of natural light.
  • Device with GIMP loaded [I use GIMP 2].

Setting up GIMP:

  1. Projects like these need air. Open a window. Specifically the Layers window… assuming it’s not already open. You’ll need more windows open, so add the following tabs via Windows, Dockable Dialogs —
    1. Channels
    2. Colors
    3. Fonts
    4. Selection Editor
    5. Tool Options

They don’t have to be in this order — I simply found this order the easiest.

Let’s turn your art into a png I’m going to use this cupcake design. You’ll notice, the design is just black, penciled line-art. There is a different technique if this cupcake were colored in. Refer to image below as a brief guide as you progress through the instructions.

  1. With your line art open, go to the Layers tab; add a Transparency layer. Now click Adobe_Post_20180724_132753.jpgon the layer containing your artwork to select it.
  2. Switch to the Channels tab. Right-click the Blue Channel and Duplicate it. Turn the duplicate channel on by clicking the box to the left of “Blue Channel” — the box should have an eye in it. Turn off all other channels.
  3. Click the pink box in the lower right of the Channels tab. You should see marching ants around your image.
  4. Switch to Selection Editor tab. Invert the selection.
  5. Switch to Layers tab. Delete your art. Switch back to Selection Editor tab; click the red x near the bottom left to dismiss selection. You should see your drawing on a gray checkerboard background.

I’ve found I don’t always need steps 3-5 for line art.

If you need to darken the lines of your image, hop back into Layers tab and duplicate the art layer. Do not duplicate more than 3 times, or you may lose some of the integrity of the image. If it doesn’t darken enough, open a New document, transparent background. In your original document, be certain your art layer is selected, then click Edit, Copy Visible. In the new document, click Edit, Paste Into, then click the New Layer button and your image will appear. Duplicate the layer once or twice and you’re good to go.

Colored art is different than line drawings — I’m going to use the Waffle Cake design for this example. This one is a little tricky, but it can be done. Let’s say you have a piece of white paper, and you color in a square in the center of it. The goal is to remove the white background, making it transparent so that you can then place the image on whatever background you need. Refer to image below for a brief guide.

  1. Add a transparent “alpha” layer. Go to Layers — Add Alpha Channel [or right click Adobe_Post_20180724_141340.jpgon the layer, it should be in the drop down].
  2. Go to Tools — Selection — Fuzzy Select. In your dockable dialogs, click on the Tool Options tab. Click the Add To Selection box. [2nd pink square next to “Mode:”]. Click the background to check Threshold. The higher the threshold, the more background is selected by clicking.
  3. Now, press the Delete button on your keyboard and watch your background fall away.
  4. In your tabs, click on Selection Editor. You’ll see that a black copy of the image shows up in the Dockable Dialogs. Click the red X at the bottom of the Dialog and the marching ants surrounding your image will disappear.

Looking to take your colored art to the next level with further steps to accurately smooth and balance it for print? Check out this awesome tutorial from GIMP Tips.

For more information and tutorials, I recommend checking out Artist Shops tutorials on Threadless.

Thank you for reading, and if you’ve additional questions the above links don’t cover, please let me know in the comments below. Even if I don’t have the answer, perhaps we can find it together.