diff --git a/lib/gruff/line.rb b/lib/gruff/line.rb
index f112687e..3daddb3f 100644
--- a/lib/gruff/line.rb
+++ b/lib/gruff/line.rb
@@ -158,7 +158,7 @@ def data(name, data_points = [], color = nil)
   # @rbs x_data_points: Array[nil | Float | Integer] | Array[[nil | Float | Integer, nil | Float | Integer]] | nil
   # @rbs y_data_points: Array[nil | Float | Integer] | nil | String
   # @rbs color: String
-  def dataxy(name, x_data_points = [], y_data_points = [], color = nil)
+  def dataxy(name, x_data_points = [], y_data_points = [], color = nil, line_width = nil)
     # make sure it's an array
     x_data_points = Array(x_data_points)
 
@@ -174,7 +174,7 @@ def dataxy(name, x_data_points = [], y_data_points = [], color = nil)
     raise ArgumentError, 'x_data_points.length != y_data_points.length!' if x_data_points.length != y_data_points.length # steep:ignore
 
     # call the existing data routine for the x/y data.
-    store.add(name, x_data_points, y_data_points, color)
+    store.add(name, x_data_points, y_data_points, color, line_width)
   end
 
 private
@@ -231,6 +231,8 @@ def draw_graph
     circle_radius = @dot_radius || clip_value_if_greater_than(@columns / (store.norm_data.first.y_points.size * 2.5), 5.0)
 
     store.norm_data.each do |data_row|
+      data_row_stroke_width = stroke_width
+      data_row_stroke_width = data_row.line_width if data_row.respond_to?(:line_width) && data_row.line_width
       prev_x = prev_y = nil
       data_row.coordinates.each_with_index do |(x_data, y_data), index|
         new_x = begin
@@ -253,13 +255,13 @@ def draw_graph
         new_y = @graph_top + (@graph_height - (y_data * @graph_height))
 
         if contains_one_point_only?(data_row) || !@hide_dots
-          Gruff::Renderer::Dot.new(renderer, @dot_style, color: data_row.color, width: stroke_width).render(new_x, new_y, circle_radius)
+          Gruff::Renderer::Dot.new(renderer, @dot_style, color: data_row.color, width: data_row_stroke_width).render(new_x, new_y, circle_radius)
         end
         if !@hide_lines && prev_x && prev_y
           # Renderer::Polyline may cause unknown lines to be drawn with complex graphs.
           # Probably it is related to ImageMagick behavior.
           # To avoid this problem, we use the Renderer::Line instead.
-          Gruff::Renderer::Line.new(renderer, color: data_row.color, width: stroke_width)
+          Gruff::Renderer::Line.new(renderer, color: data_row.color, width: data_row_stroke_width)
                                .render(prev_x, prev_y, new_x, new_y)
         end
         prev_x = new_x
diff --git a/lib/gruff/store/xy_data.rb b/lib/gruff/store/xy_data.rb
index d3352d06..ecefd7bb 100644
--- a/lib/gruff/store/xy_data.rb
+++ b/lib/gruff/store/xy_data.rb
@@ -10,12 +10,14 @@ class XYData
       attr_accessor :x_points #: Array[nil | Float | Integer]
       attr_accessor :y_points #: Array[nil | Float | Integer]
       attr_accessor :color #: String
+      attr_accessor :line_width #: Integer
 
       # @rbs label: String | Symbol
       # @rbs x_points: Array[nil | Float | Integer] | nil
       # @rbs y_points: Array[nil | Float | Integer] | nil
       # @rbs color: String
-      def initialize(label, x_points, y_points, color)
+      # @rbs line_width: Integer
+      def initialize(label, x_points, y_points, color, line_width = nil)
         y_points = Array(y_points)
         x_points = x_points ? Array(x_points) : Array.new(y_points.length)
         raise ArgumentError, 'x_points.length != y_points.length!' if x_points.length != y_points.length
@@ -24,6 +26,7 @@ def initialize(label, x_points, y_points, color)
         @x_points = x_points
         @y_points = y_points
         @color = color
+        @line_width = line_width
       end
 
       alias points y_points
@@ -82,7 +85,7 @@ def normalize(minimum_x:, minimum_y:, spread_x:, spread_y:)
           y.nil? ? nil : (y.to_f - minimum_y.to_f) / spread_y
         end
 
-        self.class.new(label, norm_x_points, norm_y_points, color)
+        self.class.new(label, norm_x_points, norm_y_points, color, line_width)
       end
     end
   end