While looking up whether JW nurses are allowed to administer blood transfusions I found this little gem from
Watchtower 15th November 1964 page 681
''The use of blood in adhesives for manufacturing plywood and other commonly used materials has now come to the attention of Christians, and we use plywood as an example.
Much plywood is made using blood glue, but some plywood is blood-free.
A Christian purchaser or contractor may seek to obtain blood-free plywood if he can do so; however, if he decides to use all types of plywood, it must be left to his conscience. It is not always possible to determine just how the plywood has been made.
Because blood may be used in some plywood, this does not mean that a Christian could not buy, sell or rent a home or purchase a trailer in which plywood is found. The extent to which he would check on such matters is for him to decide.''
Well that's must have been a relief to know. Thank you Watchtower.