How to change the linewidth of a hatch in Matplotlib?

To change the linewidth of a hatch in matplotlib, we can set the linewidth of the hatch using plt.rcParams['hatch.linewidth']. This parameter controls how thick or thin the hatch lines appear in your plots.

Steps

• Set the figure size and adjust the padding between and around the subplots
• Create x and y=sin(x) data points using numpy
• Set the linewidth of the hatch using plt.rcParams['hatch.linewidth']
• Plot x and y data points using scatter() method with a square marker having "/" hatches with set linewidth
• Display the figure using show() method

Example

Here's how to create a scatter plot with custom hatch linewidth ?

import numpy as np
from matplotlib import pyplot as plt

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

x = np.linspace(-5, 5, 25)
y = np.sin(x)

# Set the linewidth of the hatch
plt.rcParams['hatch.linewidth'] = 1

plt.scatter(x, y, s=700, marker='s', linewidth=0.05, facecolor='red',
           hatch='/', alpha=.7)
plt.show()

Comparison of Different Hatch Linewidths

Let's compare different hatch linewidth values to see the visual difference ?

import numpy as np
from matplotlib import pyplot as plt

fig, axes = plt.subplots(1, 3, figsize=(12, 4))

x = np.linspace(-2, 2, 10)
y = np.sin(x)

linewidths = [0.5, 2.0, 4.0]
titles = ['Thin (0.5)', 'Medium (2.0)', 'Thick (4.0)']

for i, (lw, title) in enumerate(zip(linewidths, titles)):
    plt.rcParams['hatch.linewidth'] = lw
    axes[i].scatter(x, y, s=500, marker='s', facecolor='lightblue',
                   hatch='///', alpha=0.7, edgecolor='black')
    axes[i].set_title(f'Hatch Linewidth: {title}')
    axes[i].grid(True, alpha=0.3)

plt.tight_layout()
plt.show()

Different Hatch Patterns with Custom Linewidth

You can also combine different hatch patterns with custom linewidths ?

import numpy as np
from matplotlib import pyplot as plt

fig, ax = plt.subplots(figsize=(10, 6))

# Set custom hatch linewidth
plt.rcParams['hatch.linewidth'] = 2.5

patterns = ['/', '\', '|', '-', '+', 'x', 'o', 'O', '.', '*']
colors = ['red', 'blue', 'green', 'orange', 'purple', 'brown', 'pink', 'gray', 'cyan', 'yellow']

for i, (pattern, color) in enumerate(zip(patterns, colors)):
    ax.bar(i, 1, hatch=pattern, facecolor=color, alpha=0.6, edgecolor='black')

ax.set_xlabel('Hatch Pattern Index')
ax.set_ylabel('Height')
ax.set_title('Different Hatch Patterns with Linewidth = 2.5')
ax.set_xticks(range(len(patterns)))
ax.set_xticklabels(patterns)

plt.tight_layout()
plt.show()

Key Points

Conclusion

Use plt.rcParams['hatch.linewidth'] to control the thickness of hatch lines in matplotlib plots. Higher values create thicker hatch lines, while lower values create thinner, more subtle patterns.