Open your digital butterfly images in an image editing program. If you don't have any digital butterfly images on hand, you can find images at educational nature websites or you can scan images from picture or reference books.
Click on the toolbar option for "Filter," choose "Sketch" from the resulting drop-down menu and then click "Photocopy" if you're using Photoshop. In Paint Shop Pro, click on "Effects" in the toolbar, choose "Edge Effects" and click on "Find All." Both methods result in an outlined version of the original image.
Adjust the levels to make the outlines on your image bolder. In Paint Shop, select "Adjust," then "Brightness and Contrast" and then "Levels." In Photoshop, select "Layers," "New Adjustment Layer" and then "Levels." Using the image preview window that both programs provide, adjust the levels until the lines are dark enough and the white areas are bright and clear enough for coloring.
Repeat this process with your remaining butterfly images. If you don't have either program, or want to save time, you can download premade butterfly coloring page images from educational websites. Save all the images into one folder as you complete their outlines.
Open the folder containing all of your outlined images. Select all the images. Right-click on your selected images and select "Print." Select "Full Page Photo," and then "Print" to print your completed images.
Gather all your pages into a single stack, each with the images facing upward. Staple the pages together vertically along the left side of the pages. Cover the staples with a strip of colored tape. Apply the tape vertically down the length of your book's spine, leaving half the tape's width hanging over the left side. Fold the strip of unattached tape over the side of the spine, so that it covers the staples on the back, too. Your DIY butterfly coloring book is now complete and ready for a generous application of crayon or marker ink.