Anyone familiar with Pellon 30 or 40?
 

I would like to make a sampler of all my decorative stitches.
Therefore I don't need anything too fancy.
Would Pellon 30 or 40 work as stabilizer?
I checked the Pellon website and it doesn't say anything
about decorative stitches. Please help.

What stitches are you talking about? Are you making them from a sewing machine or an embroidery machine?
For my Janome MC6600 - I just used a double layer of fabric and didn't need a stabilizer. If I was going to do it for my embroidery machine I would find a medium stabilizer, most of it could be done with a light cut away stabilizer.

I don't see why not

I'm sewing on a Janome 9400. Some stitches look fine without stabilizer and
others don't. Never thought of doubling the fabric. Thanks.