... that TAPPI maintains a listing of suppliers who claim to provide equipment and supplies for TAPPI Test Methods?

From the General Standards Page on the TAPPI web site you will find links to the Supplier Directory and the Test Equipment Supplier List. The Directory provides the contact information for each supplier. The Test Equipment List shows the suppliers for each TAPPI Test Method (listed in order by number).

If your company supplies equipment or materials for TAPPI Test Methods, and you are currently not listed, please send a message to the Standards Department (standards@tappi.org) and provide the contact information and the numbers of the TAPPI Test Methods for which you supply equipment. Please also indicate if you provide compete equipment or partial equipment. We will be happy to add you to the list.