Application of filler?

[ZipLock]

What do you use to apply filler? Not the putty knife, but the thing you hold in the other hand that the filler rests on. I've used a piece of OSB board, but the disadvantage with that is that small wood splinters get into the filler.

 

[ullet]

I usually use a different spackelspade.

 

[Nimajneb]

I usually have a wider one and a narrower one so you can also switch between them.

 

[ZipLock]

Ok, thanks for the tips!