I tried setting the MarkerToolTipFormat to "{Value:G}" but nothing gets displayed. However if I change it to "Value = blah" the string does get displyed. Using this code for the tooltipformat seems to work fine: layer.ToolTipFormat = "{Layer.Title}"; but using the {} to reference anything in my GaugeReading object (using {Layer.Title} works fine) seems to prevent anything from the MarkerToolTipFormat from displaying. Am I not referening the object correctly?

There may be a way to reduce the width of those axis label panels to 0 or near zero, I'll have to check that version of the chart to make sure. The way they are structured has changed since the CTP.

You shouldn't need {} when you are setting the property programattically. {} is required when you set the property from Xaml to let the Xaml parse know that your attribute that starts with a { is NOT a markup extension. Those characters are not passed along to the actual property. So try:

layer.MarkerToolTipFormat = "{Value:G}";

-Graham

I havent tried rendering the Y axes transparently as having more then one still takes up space and pushes the chart over even if I get it to be a transparent color, right?

Along these lines I cannot seem to even get the marker tooltips to be displayed. Pretty much everything is being added programatically so what I pass to the chart area is a Queue<GaugeReadings>. I am uncertain what to set the MarkerToolTipFormat to inorder to display the value. Here is the GaugeReading structure:

public class GuageReading
{
    public DateTime Time { get; set; }
    public double? Value { get; set; }
    public string Units { get; set; }
}

I set it up this way:
layer.ValueMapping = "Value";
layer.MarkerToolTipVisibility = System.Windows.Visibility.Visible;
layer.MarkerToolTipTemplate = Resources["MarkerToolTipTemplate"] as DataTemplate;
layer.MarkerType = MarkerType.Circle;
layer.MarkerToolTipFormat = "{}{Value:G}";
layer.ToolTipTemplate = Resources["ToolTipTemplate"] as DataTemplate;
layer.ToolTipFormat = "{Layer.Title}";

Can you see a problem with my marker tool tip format? How do I get it to display the marker Y value?