In this article I’ll be showing you how to add a drop shadow effect in GIMP using a built-in filter. Drop shadows can be added to text, as well as any object or layer with multiple objects – so long as that layer has an alpha channel (more on that momentarily).
I’ll demonstrate how to use this effect by showing you how to add a drop shadow to text.
Setting Up Your Text/Composition
First, let’s create a new composition. I can do this by going to File>New (red arrow in the image above) or hitting the ctrl+n shortcut key on my keyboard (cmd+n on a MAC).
Next, I’ll set the dimensions of my document – 1920 for the width, and 1080 for the height (outlined in red in the above image). The unit I’m using is pixels (px). Click OK to create the document (blue arrow).
I’ll now grab the Text tool from my toolbox (shortcut key T – green arrow in the image above).
With my Text tool active, I’ll click on my composition and begin typing some text – in this case “GIMP” (green arrow in the image above). The text will be whatever your foreground color is currently set to (in my case red).
I can hit ctrl+a on my keyboard or drag my mouse across all the text inside the new text box to select it. Once selected, I can change attributes of the text – including the font, text size, color, and more. I recommend checking out my dedicated tutorial on GIMP’s Text Tool if you are unfamiliar with this tool.
With my text selected, I’ll change the font size to 500 (green arrow) and will stick with the “Gill Sans MT Bold” font (blue arrow).
Next, I’ll click and hold the first tool group in my Toolbox (red arrow in the above image) and release my mouse over the “Alignment” tool (blue arrow).
Click on the text we just created with the alignment tool (make sure you click on actual pixels of the text). Under the Tool Options, make sure the alignment tool is set to align “Relative to Image” (under the first dropdown – red arrow). Then, click “Align center of target” and “Align middle of target” to center align the text to the image (outlined in blue in the above image).
Adding the Drop Shadow to Text
With our text in place, we can now add a drop shadow to our text. To do this, make sure the text layer is active in the layers panel (red arrow). Then, go to Filters>Light and Shadow>Drop Shadow (blue arrow).
A floating dialogue will now appear titled “Drop Shadow” (outlined in blue in the image above).
The Drop Shadow filter is a GEGL filter, which means we get a live preview of the drop shadow effect on our canvas as we tweak the settings. So, you can now see our text has a drop shadow underneath it.
The first set of sliders for the Drop Shadow filter are the “X” and “Y” sliders (outlined in blue above). These sliders allow us to reposition the drop shadow under our text layer. The “X” slider changes the horizontal location of the drop shadow (i.e. the x axis), while the “Y” slider changes the vertical location of the drop shadow (i.e. the y axis).
By default, these two values will be “linked” together via the little chain icon on the fair right of the sliders (red arrow in the photo). This means that as you click and drag one slider, the other slider will change with it. For example, if I click and drag the “X” slider to the left, the “Y” slider will follow with my mouse.
Notice that the value here for X and Y can be negative. A negative value for X means the drop shadow will be to the left of center, and a negative value for Y means the drop shadow will be above the center. (A positive value for X will make the drop shadow right of center, and positive value for Y will make the drop shadow below center). In the image above, since both the X and Y values are negative, the drop shadow is up and to the left of the original text.
I can click the “Reset” button at the bottom of the dialogue to reset my values back to the default (yellow arrow in the image).
I’ll click the chain icon to unlink the chain (yellow arrow in the above image) as I want the X and Y slider values to be independent.
Now, I’ll click and drag the X slider (red arrow). The farther I drag this slider to the right, the farther away the drop shadow will be from the text (blue arrow). Notice that I can continue dragging the slider to the right even once the slider bar is full (it usually gets full around a value of 40, but the X value can be way above 40).
I can also middle-click with my mouse wheel on this value and manually type a new numerical value. For example, I’ll middle click my mouse anywhere on the x value (red arrow in the above image), use my arrow keys to navigate the cursor to the far right, hit the backspace key to delete the current value, then type 250 and hit the enter key. My drop shadow will update with this new value.
I can have one slider with a positive value and another with a negative value. So, while X is positive, I can make Y negative.
I’ll click and drag the Y slider far to the left to give it a negative value (red arrow in the above image). As I do this, the drop shadow will move higher on the composition relative to the original text. You’ll also notice at this point that the drop shadow is way outside the yellow dotted line that denoted our layer boundary (blue arrow).
As long as you are using GIMP 2.10.14 or above, GIMP will automatically adjust your layer size to fit the portion of the drop shadow that goes outside the current layer boundary.
Once again, I’ll hit the “Reset” button to be taken back to the default values.
The next slider is the “Blur Radius” slider (red arrow in the image). This slider increases or decreases the amount of Gaussian Blur applied to the drop shadow. (Gaussian blur is a popular blur filter in GIMP – so this basically just adjusts the blur amount on your shadow).
If I set the slider value to “0,” there won’t be any blur on the drop shadow and so the shadow will have crisp edges (blue arrow in the above image). Basically, the drop shadow will just look like a new, slightly offset layer of text below the original layer of text.
On the other hand, increasing the Blur radius slider value (red arrow) will add more blur to the shadow (blue arrow). Too much blur will make the drop shadow hard to see (the shadow won’t have a discernible shape). Without adding too much blur, increasing the blur radius can help make your theoretical “light source” look softer. To put it more simply, it can make the drop shadow more subtle.
I’ll hit the reset button to return to the default values.
The next two items – the “Grow Shape” dropdown box and the “Grow Radius” slider (outlined in blue in the photo) – are related to one another.
The Grow Radius slider (red arrow) allows you to increase or decrease the size of the drop shadow before blurring is applied to it. For example, I’ll increase the grow radius and you can see that the drop shadow no longer has a nice even fade (visible in the photo above).
The Grow Shape dropdown above the Grow Radius slider changes the shape of the drop shadow as it grows. By default, this is set to circle. However, if I change this to “Diamond” (red arrow in the image above), you’ll see the corners of the blur change to have a more beveled edge (rather than a nice rounded edge – blue arrow).
If I change this option to “Square” (red arrow), the edges are much blockier (blue arrow) – or more square-like rather than rounded.
I’ll once again hit reset to return to the default values.
The next option is the “Color” option, which allows you to change the color of the drop shadow. By default, the drop shadow will be black (as shadows usually are!). However, you can click on the large color swatch to pick a new color (red arrow in the image above).
You can use the Color dialogue that pops up to hand select any color you want. You can either drag your mouse around the Color Selector on the left-hand side using the one-dimensional color strip (red arrow) and two-dimensional color area (blue arrow). Or, you can manually type in numerical color channel values for any individual color channels on the right-hand side of the Color dialogue.
Note: R, G, and B stand for “Red,” “Green,” and “Blue,” while L, C, and h stand for “Luminance,” “Chroma,” and “hue,” and finally the a stands for “alpha,” which is just transparency.
You can also copy the exact color I chose here by typing in the “HTML Notation” (outline in yellow in the image above).
Once I’m ready to apply this color, I’ll click “OK.” You’ll see my drop shadow is now a light blue color.
To the right of the large color swatch is a color picker (red arrow) that lets you choose any color in your GIMP composition (so long as it’s inside the canvas area).
Below the Color options is the “Opacity” slider (blue arrow in the above image). This slider allows you to make your drop shadow either more transparent (see-through) by dragging to the left, or more opaque by dragging to the right.
You’ll see when I drag this value to the left that the drop shadow becomes more faint (yellow arrow).
When I drag the value to the right, the drop shadow becomes more pronounced. When the slider value is set to 1.0, this means the drop shadow is totally opaque (or 0% transparent).
GIMP allows you to go beyond 1.0 for this value. To understand why, let me put it this way: Up to 1.0 will affect the opacity of the main drop shadow area excluding the blur area. Between 1.0 and 2.0 will affect the opacity of the blur area. As you can see in the photo, when I drag the slider value well above 1.0 (red arrow in the above photo), the shape of the drop shadow starts to change as the blur area loses its transparency and becomes more opaque (yellow arrow).
I typically like to keep my opacity below 1.0 – so I’ll readjust this value back to something between .5 and 1.0.
Up next in the Drop Shadow dialogue is the “Clipping” dropdown (expanded and outlined in yellow in the image above). By default, this will be set to “Adjust,” which means the text layer boundary (red arrow) will adjust to fit all the pixels created by the drop shadow. This prevents the drop shadow from getting cut off.
However, I can change this value to “Clip,” which means that any drop shadow pixels that go outside the layer boundary will get “clipped” or cut off.
Below the Clipping dropdown is an area called “Blending options.” This may be collapsed for you by default, so you can click the little “+” icon to reveal this area (blue arrow in the image above). The first item here is the “Mode” dropdown (red arrow), which allows you to select a blend mode or layer mode.
The options inside this dropdown are the same as the ones you can apply to layers over in the layers panel. In other words, these options are all layer modes, only the layer mode you choose will be applied solely to the drop shadow effect and not to the entire layer. This gives you the ability to add additional effects to your drop shadow. For example, if I choose the “Dissolve” mode (yellow arrow), you’ll see that my drop shadow will now have the dissolve layer mode applied to it (red arrow).
Below this dropdown is another “Opacity” slider (red arrow). This time, the slider only allows you to choose values between 0 and 100 and effects the entire composite drop shadow. It basically takes all the effects and settings you applied in the earlier steps and merges them into a single item. You are then adjusting the opacity of that single item.
If I drag the opacity slider down, the entire composite drop shadow will become more transparent (blue arrow). If I drag the slider value up, it will become more opaque.
If I wanted to save all the settings I just created as a preset for future use, I can simply come up to the top of the Drop Shadow dialogue and click the little “+” icon (red arrow in the above image).
A box named “Save Settings as Named Preset” will appear (outlined in yellow), and I can give my preset a name. In this case, I’ll name it “Blue Dissolve.” Click OK to create the new preset.
Next to the “+” icon at the top is a dropdown (blue arrow). Here, you’ll see automatically created presets based on Drop Shadow effects you applied in previous sessions. Towards the bottom, you’ll see a divider line that separates the autogenerated presets from the user created presets. Below the divider line you’ll see the name of the new preset we just create – “Blue Dissolve” (red arrow).
At the bottom of the Drop Shadow dialogue are the “Preview” and “Split Preview” checkboxes. The preview (yellow arrow) lets you toggle the live on-canvas preview of the filter’s effects.
The “Split Preview” checkbox (red arrow), when enabled, will show a divider line on your canvas (blue arrow). On the left side of the divider is a live preview of the effect, whereas on the right side of the line is the composition before the effect was applied (i.e. a “before” version of the text).
You can click and drag this line across your canvas to change the size of the preview areas on either side of the line. For example, if I drag the line to the right, I get more of the “after” preview. If I drag it to the left, I get more of the “before” preview.
If I don’t want to apply these changes, I can click the “Cancel” button. Otherwise, when I click “OK,” the drop shadow will be applied directly to my text layer.
Notice that with the effect now on my text, the text layer itself has been converted to a standard pixel layer (meaning the text information has been discarded – red arrow in the above image). I can no longer edit my text with the text tool without undoing the drop shadow effect.