The tradition of plain covers continued into the 1970’s with some covers proving really hard to source. As an example, the Flowers of Barbados Mini Sheet FDC shown here is the only one I have ever seen.
And along with the plain covers, the practice of nonspecific cancels continued and it’s not until the Bicentennial of the American Revolution in 1976 that we see the first purpose-made cancel simply saying ‘First Day of Issue’.
Barbados 1970 4c Overprint FDC
Barbados 1970 International Education Year FDC - plain cover
Barbados 1970 Flowers of Barbados FDC
Barbados 1970 Flowers of Barbados FDC -2
Barbados 1970 Flowers of Barbados mini sheet FDC - plain cover
Barbados 1971 | Easter on plain FDC
Barbados 1971 | Tourism FDC
Barbados 1971 | IDeath Centenary of Samuel Jackman Prescod on plain FDC
Barbados 1971 | 5th Anniversary of Independence FDC
Barbados 1972 Telecommunications in Barbados FDC - illustrated cover
Barbados 1972 Boy Scout Diamond Jubilee FDC - illustrated cover
Barbados 1972 | International Book Year on plain FDC
Barbados 1973 | Pottery in Barbados on plain FDC
Barbados 1973 | Aviation on plain FDC
Barbados 1973 | 25th Anniversary of the university of Barbados on plain FDC
Barbados 1974 4c overprint FDC - plain cover
Barbados 1974 | Fishing Boats of Barbados on plain FDC
Barbados 1974 | Orchids of Barbados Definitives on plain FDC
Barbados 1974 | Centenary of the UPU on plain FDC
Barbados 1974 | Centenary of the UPU Souvenir Sheet on Illustrated FDC
Barbados 1974 | Centenary of the UPU Souvenir Sheet on plain FDC
Barbados 1975 | Royal Visit on plain FDC
Barbados 1975 | Crop Over Festival Block of Four with plate numbers on plain FDC - 8c
Barbados 1975 | Crop Over Festival Block of Four with plate numbers on plain FDC - 25c
Barbados 1975 | Crop Over Festival Block of Four with plate numbers on plain FDC - 35c
Barbados 1975 | Crop Over Festival Block of Four with plate numbers on plain FDC - 50c
Barbados 1975 350th Anniversary of First Settlement FDC - plain cover
Barbados 1975 350th Anniversary of First Settlement Mini Sheet FDC - Plain Cover
Barbados 1976 | Barbados Postage Due stamps on plain FDC
Barbados 1976 The American Revolution Bicentennial FDC - illustrated cover
Barbados 1976 125th Anniversary of the Post Office Act FDC - plain cover
Barbados 1976 10th Anniversary of Independence FDC - plain cover