Learn how to draw a simple cartoon knife filled with basic shadows and highlights. You will see that adding these digital effects can easily be done using a vector application. No need to draw complex shapes and add several layers of textures and details. It's simple and easy to implement! :)
You can begin by drawing two simple shapes to help you locate your object in the working space. A rectangular shape can be used to form the handle. The blade is represented by an irregular rectangle that must be pointed near the end.
We can now draw the cartoon knife using simple thick lines. Don't forget to draw two rivets on the handle using small circles. The handle is also made from curved lines that are used to imitate the shape of the hand. When you are done, you can erase both rectangles drawn previously.
For now, simply add a light brown color inside the handle and a light gray one inside the blade. Both rivets can also be colored in gray.
A simple technique to add more volume inside the knife is to use color gradients. For instance, the top part of the blade can darker and the bottom much brighter. You can apply the same recipe on the handle and inside the rivets.
Next, you can draw new dark shapes on the handle and the blade to create shadows. In the illustration below, these shapes are surrounded by a pink outline. You can also play with the opacity of these new elements to create something subtle and partially hidden.
You can also draw two large shapes colored in white to add some reflection on the cartoon knife. Once again, play with the opacity of these shapes (the final can be seen in step number 7) to end up with a very subtle result.
More reflection can be drawn on the blade (using large rectangles) and on the rivets. Now that we have a good mix of highlights and shadows, the final illustration should look pretty realistic for a cartoon illustration.
One last thing that can be done to complete this lesson is adding some texture on the handle. You can simply draw a few basic lines as shown in the illustration below. Once again, these lines can also be partially transparent for more realism.
Below you can see the final image once all effects are added. :)
Drawing an object like a knife is a good exercise, especially if you want to work on a realistic object that is shiny and loaded with simple challenges. You don't need to create tons of tiny details to end up with something believable and fun to play with. :)