Reading Time: 8 mins
Are you struggling to create dynamic visuals in your Scratch projects? The pen tool might be exactly what you need, but many beginners find it confusing or don’t even know it exists. Without mastering the pen tool, your Scratch projects may lack the visual appeal and sophistication that make them stand out.
In this comprehensive guide, we’ll walk through everything you need to know about how to use pen tool in Scratch effectively. Whether you’re a student, educator, or coding enthusiast, by the end of this article, you’ll have the skills to create stunning visual effects, interactive drawings, and even games using Scratch’s powerful pen capabilities.
The pen tool in Scratch is a powerful feature that allows sprites to draw lines and shapes as they move across the stage. Think of it as attaching a virtual pen to your sprite that can be controlled with code. Unlike the simple movement of sprites, the pen tool creates persistent marks on the stage, enabling complex visual effects, patterns, and drawings.
The pen tool has been part of Scratch since its early versions, inspired by the original Logo programming language’s turtle graphics. In Scratch 3.0, the pen tool was moved to an extension, making the interface cleaner while still providing all its powerful functionality.
Key characteristics of the pen tool include:
Understanding how to use pen tool in Scratch opens up creative possibilities that aren’t possible with sprite movements alone:
In Scratch 3.0, the pen tool functionality is available as an extension that needs to be added to your project before use.
Once added, you’ll have access to all the pen blocks needed to start drawing. The extension includes blocks for controlling the pen state, appearance, and position.
To master how to use pen tool in Scratch, you need to understand these essential commands:
The most fundamental pen commands are:
when green flag clicked
pen down
move 100 steps
turn right 90 degrees
move 100 steps
pen up
This simple script will draw an L-shape on the stage.
Customize your drawings with these appearance commands:
Now that you understand the basics of how to use pen tool in Scratch, let’s create some simple shapes:
when green flag clicked
clear
pen down
repeat 4
move 100 steps
turn right 90 degrees
end
pen up
when green flag clicked
clear
pen down
repeat 36
move 10 steps
turn right 10 degrees
end
pen up
when green flag clicked
clear
pen down
set pen size to 1
repeat 100
move 5 steps
turn right 92 degrees
change pen size by 0.1
end
pen up
These simple examples demonstrate how a few lines of code can create complex visual patterns—a key benefit of learning how to use pen tool in Scratch.
Once you’ve mastered the basics, try these advanced techniques to take your pen tool projects to the next level:
Create unpredictable yet beautiful patterns using random values:
when green flag clicked
clear
pen down
repeat 100
set pen color to (pick random 1 to 100)
move (pick random 5 to 20) steps
turn right (pick random 30 to 150) degrees
end
Variables can control your pen’s behavior, creating dynamic drawings:
when green flag clicked
clear
pen down
set [size] to 1
repeat 100
set pen size to (size)
move 5 steps
turn right 91 degrees
change [size] by 0.2
end
The pen tool excels at creating recursive patterns like fractals:
when green flag clicked
clear
pen down
set pen color to 0
draw fractal:: custom (60) (5)
With a custom block for the recursive function:
define draw fractal (length) (depth)
if (depth > 0) then
move (length) steps
turn right 60 degrees
draw fractal:: custom ((length) / 3) ((depth) - 1)
turn left 120 degrees
draw fractal:: custom ((length) / 3) ((depth) - 1)
turn right 60 degrees
draw fractal:: custom ((length) / 3) ((depth) - 1)
move ((-1) * (length)) steps
end
This creates a Koch snowflake, a famous fractal pattern that demonstrates the power of recursive drawing with the pen tool.
One of the most practical applications when learning how to use pen tool in Scratch is building your own drawing program. Here’s how to create a simple one:
when green flag clicked
clear
pen up
when [space] key pressed
if (pen down?) then
pen up
else
pen down
end
forever
go to (mouse-pointer)
end
when key [1] pressed
set pen color to [red]
when key [2] pressed
set pen color to [blue]
when key [3] pressed
set pen color to [green]
when key [up arrow] pressed
change pen size by 1
when key [down arrow] pressed
change pen size by -1
With these building blocks, users can create their own digital artwork within your Scratch project.
Even when you know how to use pen tool in Scratch, you might encounter these common problems:
If your pen isn’t drawing:
For smoother lines:
To keep drawings visible:
If your project slows down:
Looking for inspiration on how to use pen tool in Scratch creatively? Check out these project ideas:
Create a digital version of the classic drawing toy that produces mathematical curves:
when green flag clicked
clear
pen down
repeat 72
set pen color to (counter * 5)
repeat 6
move 100 steps
turn right 60 degrees
end
turn right 5 degrees
end
Generate beautiful fractal trees that mimic natural growth patterns:
when green flag clicked
clear
pen up
go to x: 0 y: -180
set heading to 0
pen down
draw branch:: custom (100) (7)
With a custom block:
define draw branch (length) (depth)
if (depth > 0) then
set pen size to (depth)
move (length) steps
turn right 30 degrees
draw branch:: custom ((length) * 0.7) ((depth) - 1)
turn left 60 degrees
draw branch:: custom ((length) * 0.7) ((depth) - 1)
turn right 30 degrees
move ((-1) * (length)) steps
end
Create an art application where different keys trigger different drawing patterns:
Use the pen tool to track and visualize the path of objects in physics simulations:
Mastering how to use pen tool in Scratch opens up a world of creative possibilities that blend coding, mathematics, and art. From simple geometric shapes to complex fractals and interactive drawing applications, the pen tool empowers you to create visually stunning projects that stand out.
Remember that the best way to learn is through experimentation—try modifying the examples in this guide, combine different techniques, and create your own unique pen-based projects. The pen tool’s simplicity makes it accessible to beginners, while its flexibility provides endless opportunities for advanced users.
Whether you’re an educator looking to engage students, a student exploring creative coding, or a hobbyist building interactive projects, the pen tool is an essential skill in your Scratch toolkit.
Ready to start drawing with code? Add the pen extension to your next Scratch project and watch your ideas come to life, one line at a time!
What’s the difference between sprite movement and pen drawing in Scratch?
Sprite movement changes the position of a character or object on screen, while pen drawing creates permanent marks on the stage as sprites move. Think of sprites as actors that can optionally leave trails behind them with the pen tool.
Can I draw different colors at the same time?
While a single sprite can only use one pen color at a time, you can use multiple sprites, each with different pen settings, to draw with multiple colors simultaneously.
How do I save my pen drawings in Scratch?
Pen drawings are part of your Scratch project. Save your project to preserve the drawings, or use the “print screen” function on your computer to capture a static image of your creation.
Can I create 3D drawings with the pen tool?
While Scratch is primarily 2D, you can create the illusion of 3D using perspective techniques, shading, and mathematical formulas to project 3D coordinates onto the 2D stage.
Is there a limit to how much I can draw with the pen tool?
Extensive pen use can slow down your project, especially on older devices. If performance decreases, consider clearing the stage periodically or using the “stamp” function instead of continuous drawing.
How can I draw smooth curves instead of straight lines?
For smooth curves, use small movements with small angle changes. The smaller the steps and turns, the smoother the resulting curve will appear.
Can the pen tool interact with sprites and detect colors?
The pen itself doesn’t detect collisions, but you can use Scratch’s “touching color” blocks to have sprites interact with pen drawings.
How do I erase specific parts of my pen drawing?
The “clear” block erases all pen marks. For selective erasing, you can draw over existing marks using a pen color that matches the background or create a sprite that acts as an eraser.
