Show or hide an effect
You can show or hide effects on the artboard the same way that you can show or hide any object in the Objects and Timeline panel. Hiding an effect enables you to quickly see how your object looks without the effect applied.
You can turn off the rendering of all effects on the artboard if you have applied effects to numerous objects and notice that the response time of Microsoft Expression Blend is reduced.
At the bottom of the artboard, click Turn off rendering of Effects .
You can also maintain a good response time in Expression Blend by setting a zoom limit above which effects will automatically be turned off. On the Tools menu, click Options, click Artboard, and then, under Effects, set the Zoom threshold.