Thank you for taking time out to look for me Nigel.
I'll glassine the suspects , just in case.
The 3c Liberty there's something definitely going on there.
If I come across any news, or mail from blogs , I'll post
I'll also post after looking for fibres.
Glossary
To economise paper stock during the 1914-18 war, paper of poor quality was used for the manufacture of French and French colonial stamps. Introduced late in 1916, sheet margins bore the initials G.C., and postmasters were advised to use extra care in handling. The papers varied in tone and quality, the commonest being a greyish newsprint recognisable in the stamps at a glance, but others of better quality, white and cream, are not easily distinguishable unless with "G.C." margin.
Paper examples and Fibres
http://blog.stampmagazine.co.uk/201...archive.html