method Button.Skin (State as StateEnum, File as String)
Specifies the skin file to display the specified state.

TypeDescription
State as StateEnum A StateEnum expression that indicates the state skin to be changed.
File as String A string expression that specifies the path to a skin file ( *.ebn ), a string expression that indicates the BASE64 encoded string that holds a skin file ( *.ebn ). Use the Exontrol's exImages tool to build BASE 64 encoded strings on the skin file (*.ebn) you have created. If the File parameter is an empty string the skin is erased, so your button displays only the Image and the Caption of the button without a visual appearance ( skin ). 
The button provides multiple states like: normal, pushed, hot, disabled, custom, focused and so on. Each state has an associated skin that's displayed when certain state occurs. The UseTransparency property specifies whether the control supports transparency. The transparent regions in the control's skin indicates the transparency of the button. Use the Exontrol's exButton Builder to create new skins for your button. Use the ForeColorState property to assign a different foreground color for certain state. Use the UseFocusSkin and FocusSkin properties to change the button's visual appearance when the control has the focus. Use the SkinV method to load EBNs from resources.

Please be aware that Style property changes the following properties, based on the style chosen:

The following sample displays only the exPressed skin when the user clicks the button:

With Button1
    .Caption = "&Help"
    .Style = exXPBlue
    .AllowHotState = False
    .UseFocusSkin = False
    .Skin exNormal, ""
End With 

We would recommend taking a look over the following articles: