A realistic rat drawing portrays a cute, intelligent, and often misunderstood animal. While there are many ways to learn how to draw a rat, this lesson will simplify the process as much as possible with an emphasis on realism.
A common theme of death in the Western world due to the Black Plague, rats are actually clean, tame, and very playful. On the other side of the spectrum, rats are revered in some Asian cultures. For example, the zodiac features the rat/mouse to symbolize intelligence, ambition, and creativity.
So depending on what you want to use your realistic rat drawing for, there are some deep cultural significances that you can add to your finished product. For others, it is just a fun little animal to draw.
Size wise, a rat is larger than a mouse. This means a common difference you need to focus on is a much larger, more refined, body structure in comparison to the head and a thicker tail. Keep these traits in mind.
This first step in learning how to draw a rat will require you to simply sketch out the rat as roughly as possible. Focus on the overall form and proportions from the description given above.
On a new layer, you can make circles for joints, triangles for the head, and squares to join everything together. Imagine the bone and muscle structures underneath as you start creating some simple gesture lines for the direction of the fur.
If we are using the head as a measurement, proportion wise, the body is around lengths longer and two heads thicker than the head. At the end of things, the tail is approximately the same length as the entire animal.
Once you have the rough sketch from the descriptions, create a new layer underneath, fill it up with a neutral color (using 100% pressure), and start blocking in simple shaded areas. Merge both layers when you are done.
Personally, I like this part because you can use your gesture lines to turn it into noticeable fur using the smudge tool. Using the chalk brush tip, go ahead and begin gently smudging the entire realistic rat drawing carefully in the direction of the gesture lines.
Longer smudges can be used to for the body. However, when moving towards the head, switch over to a smaller brush and smudge in smaller strokes to simulate shorter fur. When most of the rough lines are gone, begin working on the details.
Well defined areas like the fingers, muzzle, and tails will need to refined using the eraser tool to give it a sharp edge. After that, draw a few lines on the tail to give it some texture. Lock the layer down so you don't accidentally draw outside of its boundaries.
You can also begin to draw in some details of the face like the ears and the nose. Darken the eye spots as needed to complete the smudged base. From here on, we will be using this base to draw the remaining fur and other small details.
There are many ways to draw small fur. To cover a large area, use a sponge brush tip. Simple gloss over a large area very lightly with this brush tip for the initial fur. Then, choose targeted areas to enhance the fur on the limbs.
Should it look too uniform, you can always swap to a small brush and do quick bursts of brush strokes to give the appearance of individual hair. Do the strokes in the same manner and direction as how you smudged the fur.
This is also a good opportunity to work on shading the underbelly. With the layer still locked, use a dark hue and draw in the shaded patches of small fur. The eyes can be drawn easily by adding a white patch where the eye reflections are roughly located.
In the final stages, go ahead and unlock the layer so you can start drawing in the whiskers once you are done with the fur. Keep on repeating the above steps until it all the details looks correct to you.
By now, the picture should be coming along very nicely. In this final step, we are going blend it with the background and make it realistic with proper light and shadow effects. There are many ways to do this depending on your software.
For one, you can duplicate the realistic rat drawing on a different layer, draw the light and shadows (preserving the transparency so you can't paint outside of the boundaries, of course), then adjusting the opacity, and then re merging it to the original realistic rat drawing.
If you are using Photoshop, you can simple draw the light and shadows on a separate layer and then turn the layer into a clipping mask. This will preserve the textures of the rat while allowing you to play around with shading on a separate layer.
Regardless of the method you are using, the idea here here is to show where the light will hit and where the shadows are more predominant. For example, the light is most needed on the muzzle to create a nose bridge.
The tail can also use a bit of work. Some simple criss cross lines should give it a quick illusion of scales when looked at from a distance. If needed, you can also adjust the contrast and brightness to bring out or hide certain features.
Another trick that you can use to bring out the fur a bit more is to sharpen the textures with either the sharpen tool or a global sharpening filter. Whatever you need to do, just continue to draw anything that seems out of place until it is perfect.