How to Make a Line Thicker in Photoshop

As an Amazon Associate we earn from qualifying purchases.

Lines are one of the best ways to add some artwork to your photos. Whether using pre-existing lines or drawing custom lines, knowing how to make a line thicker in Photoshop will help you create a line that will fit your artwork.

How to Make a Line Thicker in Photoshop 

A line is one of the basic design tools in Photoshop that allows you to connect two elements or points. Usually, the line has texture, tone, length, and width. In Photoshop, the line width is referred to as the line thickness.

An image of computer

The default Photoshop lines are thin, and you might need to make them thicker to blend into your project. Since Photoshop is a flexible and versatile photo-editing application, it lets you edit and make a line thicker using the following varying methods.

Using a Selection

A Photoshop selection is an area you define in your image or document, allowing you to make edits without affecting the rest of the document. Usually, this is the best method to use if you’re working with a pre-existing line, such as a downloaded line artwork.

Photoshop has different selection tools such as marquee, subject selection, magic wand, and quick selection tools. Although the best selection tool will depend on the project’s complexity, use these tips to select using the quick selection tool if the artwork has defined lines.

Open the Line Image in Photoshop

Open Photoshop, navigate to File, and then select Open. From the Windows Explorer that pops up if you’re using a Windows PC or the mac finder that pops up if you’re using a Mac, locate and select the line image you want to thicken and then choose Open.

Usually, the image will open as the background layer by default. Considering that Photoshop is a destructive photo manipulation application that affects the image pixels, it’s advisable to duplicate the background layer so you can work on a new layer.

Go to Layer and then select Duplicate Layer. Alternatively, you can press the keyboard keys Ctrl + J if you’re using a PC or Command + J if it’s a Mac. It is advisable to rename the new layer to keep your workflow organized.

Pick the Quick Selection Tool

The Photoshop quick selection tool uses advanced algorithms to detect where a certain color in the image starts and ends, helping it figure out an object’s beginning and end. That means the tool can easily detect your line object regardless of the color.

Choose it from the toolbar on the left side of the Photoshop workspace. This tool looks like a paintbrush and is usually the fourth option on the list. Alternatively, you can pick it by hitting the W key on your keyboard.

If you see a magic wand icon when you hit the W key instead of the quick selection tool icon, right-click on it and then pick the quick selection tool.

An image of a person typing

Make a Selection

Since you want your selection to be smooth for a smoother line edge, ensure you select the Enhance Edge option located at the options bar. Click and drag the tool on your image to make a selection of the line object.

Depending on the complexity of the image you are working on, you might need to add or subtract from the selection by clicking on the brush-and-dotted-line icon at the top of the screen.

The icon with a plus sign tells the tool to add a selection to the existing one when you click on the image, and the icon with a minus sign tells it to subtract from the selection. When you release the mouse, you will see your selection as indicated by a continuous line of marching ants.

Expand the Selection

After making the selection around the lines, you can make the line thicker by expanding the selection. Navigate to Select, choose Modify, and click on Expand to open the selection expansion dialog box.

In the Expand By textbox, enter the number of pixels you want to expand your lines by and then click OK to confirm. Usually, this will expand the selection and move the line of marching ants away from your image line depending on the number of entered pixels.

Match the Colors

With the selection expanded, use the following steps to match the color of the selection to the color of the existing line to make the line look natural and realistic.

  1. Navigate to the Layers panel, click on the Adjustment icon, and then select solid color
  2. Choose a color from the color picker window that pops up, and then click on OK to confirm
  3. If the foreground color matches that of the line, you can use the keyboard shortcut keys Option + Delete if you’re using a Mac or Alt + Backspace if you’re using a Windows PC.
  4. With the line expanded, looking smooth and natural, you can deselect by hitting Ctrl + D if you’re using a PC or Command + D if it’s a Mac. With the selection removed, you can continue with other edits or save the image

Using the Minimum Filter

Since the Photoshop minimum filter helps to modify the masks, it can let you thicken the lines. Open the line artwork, use the above tips to duplicate the background layer, and then use the following steps to thicken the line using the minimum filter. 

  1. With the duplicate layer highlighted, go to Filter, choose Other, and then select Minimum to open the minimum filter dialogue box.
  2. Move the Radius slider to the right to increase the thickness of the line. Keep in mind that even the lowest Radius slider setting of one pixel can still increase the thickness of the line.
  3. Keeping in mind that you might not be sure of how many pixels you need to input, it’s advisable to enable the preview by clicking on the box besides Preview so you can view the thickness of the line as you move the slider.
  4. The Preserve option lets you choose the shape of the line. However, since it can be challenging to notice the shape of a thin line, it is advisable to choose the shape after increasing the line thickness. Typically, you can set the line to Roundness or Squareness.

Using the Line Tool

Sometimes you might draw custom lines in Photoshop using the Line Tool rather than editing pre-existing line images. The Photoshop line tool is versatile and allows you to change the line thickness before drawing the line.

An image of a man working

After picking the line tool, click the drop-down arrow next to the pixel text box in the options bar. Make the line thick by entering the number of pixels in the text box or moving the thickness slider to the right.

Frequently Asked Questions

Can I Increase the Thickness of a Line in Photoshop After Drawing?

You can increase the thickness of a line in Photoshop after drawing by selecting the line layer in the layers panel, choosing Windows, and then Properties to open the properties panel. Move the thickness slider to the right to increase the thickness.

Can I Make a Line Thinner in Photoshop?

You can make a line thinner in Photoshop using the maximum filter or selecting it with a selection tool and then contracting the selection. You can also make a custom-drawn line thinner by moving the Line Tool thickness slider to the left.

Final Thoughts

Knowing how to make a line thicker in Photoshop can help you use varying line thicknesses to create impressive artwork and effects. You can increase the thickness of the line using a selection tool, minimum filter, or moving the Line Tool thickness slider to the right.