Debra,
To be brief, they are not acid free and will embrittle and fox like newspapers. There are so many wonderful substrates out there for pastel.
The only mats that are archival are the ones specifically manufactured as such. Only certain companies manufacture them and none are sueded.
Unless you are doing them just for fun and not for resale or commissions they are OK I guess.
I have started a
thread just on pastels, materials, substrates, etc. There are some suggestions for pastel surfaces.
www.dakotapastels.com has wonderful stuff.
The worst place to be cheap is in your materials, especially the substrate.
I would love you to comment on your experiences with the Ludwig Pastels on that
thread .
Sincerely,