Glad to be of help.
The 1918-1921 Bank of Ireland notes
were smaller, approximately 150x100mm, though the higher denominations were still large sized. these small sized BoI notes were still printed on handmade paper, so were slightly irregular sized with rough edges.
Notes of the other banks in this era 1918-1920, National Bank
, for example became smaller also, approximately 145x85mm. These notes were sheet printed, thus with regular edges when cut.