Unable to use Artistic Filters

[petnatcar]

Any reason why I can't activate the Artistic Filter in Photoshop 6.0?

I created a print with the spatter brush from a photograph that was scanned but now I'm unable to duplicate the procedure.
The "Artistic Brushes" remain "greyed out" unless I turn on the quick mask which then masks the layer and leaves me unable to add the filter.
I made a duplicate layer of the image and selected the image but
am still unable to get the filter to work.
Why is this happening?
I know it's something simple but I'm a novice with this program
am still trying to figure it out.

Thanks for your help,
Peter

[BlueFlare]

In the menu make sure image/mode/rgb and image/mode/8 bits/channel is selected .

[petnatcar]

I got it.
Thanks man.
It works great again.
I knew it was something simple.
Mode has to be RGB.

Why?

[BlueFlare]

I got it.
Mode has to be RGB.

Why?

Because some filters only work in RGB.

[michael-nakhleh]

and why 8 bits?? please

[handrawn]

basically because that is the maximum [or maybe only] color depth some filters support - this will depend on the filter