title: In GDI+ a "Parameter is not valid." on setting pen.Width
body: <p>I have a <code>System.Drawing.Pen _pen</code>.</p>
  
  <p>When in some iterations is setting <code>_pen.Width = 3</code> it gives me:</p>
  
  <pre><code>System.ArgumentException 
    Message="Parameter is not valid."
    Source="System.Drawing"  - System.Drawing.dll
    StackTrace:
         at System.Drawing.Pen.set_Width(Single value)
         at MyProject.ctlPanneauGraphique.CustomLine.set_BorderWidth(Int32 value) in 
         ....
         at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
         at MySolution.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
         at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
         at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
         at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
         at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
         at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
         at System.Threading.ThreadHelper.ThreadStart()
  </code></pre>
  
  <p>What and why?</p>