Modifying default tab size in RichTextBox

private void Form1_Load(object sender, EventArgs e)
{
    richTextBox1.SelectionTabs = new int[] { 100, 200, 300, 400 };
}

richTextBox1.Text = "t1t2t3t4";
richTextBox1.SelectionTabs = new int[] { 100, 200, 300, 400 };

richTextBox1.SelectionTabs = new int[] { 100, 200, 300, 400 };
richTextBox1.Text = "t1t2t3t4";