diff --git a/src/Barcode.php b/src/Barcode.php
index a39b382..5b210b3 100644
--- a/src/Barcode.php
+++ b/src/Barcode.php
@@ -14,6 +14,7 @@ public function __construct(string $barcode)
         $this->barcode = $barcode;
     }
 
+    // Add a bar to the barcode, either a bar or a space, at the right side of the barcode
     public function addBar(BarcodeBar $bar): void
     {
         $this->bars[] = $bar;
diff --git a/src/BarcodeBar.php b/src/BarcodeBar.php
index 58a881f..28bd595 100644
--- a/src/BarcodeBar.php
+++ b/src/BarcodeBar.php
@@ -2,6 +2,7 @@
 
 namespace Picqer\Barcode;
 
+// Represents a single bar or space in a barcode
 readonly class BarcodeBar
 {
     protected int $width;
diff --git a/src/Renderers/DynamicHtmlRenderer.php b/src/Renderers/DynamicHtmlRenderer.php
index 51ea1a0..66a3e52 100644
--- a/src/Renderers/DynamicHtmlRenderer.php
+++ b/src/Renderers/DynamicHtmlRenderer.php
@@ -36,8 +36,10 @@ public function render(Barcode $barcode): string
         return $html;
     }
 
-    public function setForegroundColor(string $color): void
+    public function setForegroundColor(string $color): self
     {
         $this->foregroundColor = $color;
+
+        return $this;
     }
 }
diff --git a/src/Renderers/HtmlRenderer.php b/src/Renderers/HtmlRenderer.php
index 517908e..77ba389 100644
--- a/src/Renderers/HtmlRenderer.php
+++ b/src/Renderers/HtmlRenderer.php
@@ -36,8 +36,10 @@ public function render(Barcode $barcode, float $width = 200, float $height = 30)
         return $html;
     }
 
-    public function setForegroundColor(string $color): void
+    public function setForegroundColor(string $color): self
     {
         $this->foregroundColor = $color;
+        
+        return $this;
     }
 }
diff --git a/src/Renderers/PngRenderer.php b/src/Renderers/PngRenderer.php
index 22cfcc8..8297d88 100644
--- a/src/Renderers/PngRenderer.php
+++ b/src/Renderers/PngRenderer.php
@@ -32,17 +32,19 @@ public function __construct()
     /**
      * Force the use of Imagick image extension
      */
-    public function useImagick(): void
+    public function useImagick(): self
     {
         $this->useImagick = true;
+        return $this;
     }
 
     /**
      * Force the use of the GD image library
      */
-    public function useGd(): void
+    public function useGd(): self
     {
         $this->useImagick = false;
+        return $this;
     }
 
     public function render(Barcode $barcode, int $widthFactor = 2, int $height = 30): string
@@ -88,9 +90,11 @@ public function render(Barcode $barcode, int $widthFactor = 2, int $height = 30)
         }
     }
 
-    public function setForegroundColor(array $color): void
+    public function setForegroundColor(array $color): self
     {
         $this->foregroundColor = $color;
+        
+        return $this;
     }
 
     protected function createGdImageObject(int $width, int $height)
diff --git a/src/Renderers/SvgRenderer.php b/src/Renderers/SvgRenderer.php
index 6587d99..6af44b3 100644
--- a/src/Renderers/SvgRenderer.php
+++ b/src/Renderers/SvgRenderer.php
@@ -49,17 +49,19 @@ public function render(Barcode $barcode, float $width = 200, float $height = 30)
         return $svg;
     }
 
-    public function setForegroundColor(string $color): void
+    public function setForegroundColor(string $color): self
     {
         $this->foregroundColor = $color;
+        return $this;
     }
 
-    public function setSvgType(string $svgType): void
+    public function setSvgType(string $svgType): self
     {
         if (! in_array($svgType, [self::TYPE_SVG_INLINE, self::TYPE_SVG_STANDALONE])) {
             throw new InvalidOptionException();
         }
 
         $this->svgType = $svgType;
+        return $this;
     }
 }