These are polished copper plates (measuring 6 x 9 cm and 0.8mm thick) with their protective plastic covering. The first thing that needs to happen is to round the edges off so that the plate doesn't damage the felt on the etching press.
Next the plates are rubbed down with fine wire wool so that the etching ground 'attaches' itself to the plate.
Now the plates need to be thoroughly cleaned, first with turpentine and then with methylated spirit, before the etching ground can be applied.
Once the plates are dry, the etching ground can be applied. The engraving will be made into this layer, not the copper itself. This layer will protect the plate when it's placed in the acid bath, so that the acid only bites into the copper where the line sketch has been made. In this case we are using a hard ground. Now they have to dry (overnight)... next step to follow!