They will be greyed out if they are not identical in all fields selected. This can depend on a related formatting field being different.

One workaround is to create an internal text parameter:

![FontFamily Internal Parameter][1]

With default value of the value you want to use for the property:

![FontFamily Internal Parameter Default Value][2]

Then set the property for each cell that should have the same formatting to this parameter individually:

![Textbox properties with parameter][3]

Repeat this for each of the relevant child properties, you will then be able to change formatting across the report by changing the parameters.

  [1]: http://i.stack.imgur.com/1DgFj.png
  [2]: http://i.stack.imgur.com/VscYN.png
  [3]: http://i.stack.imgur.com/ki2O4.png

This is very similar to the post on [Formatting multiple fields at once in RDL][1], but there are still issues with setting properties like `Size.Width` and `Font.FontSize` when the underlying data is different between selected cells.  

Here's the accepted answer: 

> Select all the controls in the designer and press <kbd>F4</kbd> for properties. Change the background color

But if falls short when there is a property that is made up of several child properties. Here's an example using font and size, each of which are comprised of several properties.

This is what it looks like when a single field is selected or when multiple fields are selected that all have the same value:

![Properties](http://i.imgur.com/9xBOZwy.png)

But if I highlight several cells that have different font sizes, or widths, I lose the ability to edit them all simultaneously.  For example if I wanted to make consistent column widths across an entire report.

Here's what the properties look like when multiple fields are selected and any of them have a different value:

![Properties - Hidden](http://i.imgur.com/89fOdti.png)

It's not ideal, but in the case of the size property, I can enter the shorthand value which includes both width and height separated by a comma and it will apply that change to all the selected cells.

But for some reason, in the Font section, I can't even do that.

### Other things I've tried:

* **Using the Formatting Toolbar** - which seems to be always greyed out for SSRS:  
 ![Toolbar](http://i.imgur.com/6K8e03o.png)

* **Using the Formatting Menu Item** - which doesn't expose the FontSize property:  
 ![MenuBar](http://i.imgur.com/qWzqjJm.png)

* **Using the Context Menu** to enter the Properties Form, which is disabled:  
 ![ContextMenu](http://i.imgur.com/ezFXJ7B.png)

[1]: https://stackoverflow.com/q/3681397/1366033