To me a hand made cast net is one where the maker starts with a spool of twine, a net making needle with a mesh board and hand knits the net tying every knot that it takes to make the net to the desired size.
I hear all the time a net made out of machine made webbing cut into panels and sown together called a hand made net, you be the judge.
The early Minorcans made a 21 widening net, this is a net that has 21 extra meshes added every third row. To better explain this, the net maker would start his net with 63 meshes at the top and would continue this, 10 to 12 rows down. Now he would start his widening rows by every third mesh placing an extra mesh by going in between the mesh that he had just made and the mesh that is next in line. 3 X 21 is 63 so now you see why it was called a 21 widening net. Every third row the mesh count increases by 21, so after the first widening row the count goes from 63 to 84 and so on. The net maker will continue adding these 21 extra meshes every third row until he gets to within 10 to 12 rows of the length of the net that he wants to make then adds these last rows with out widening rows. Thus a, typical 7 Ft. 21 widening net will end up with over 500 meshes around the bottom of the net.
If you did not put widening meshes in the net you would end up with a sock.
At some point in time it was discovered that you did not need this much webbing for the cast net to open properly, so net makers started making a 16 widening net. They would start with 48 meshes at the top, knit down 7 to 8 rows then add a widening after ever third mesh thus 3 X 16 is 48 so a 7 ft. 16 widening net would have just over 400 meshes around the bottom, this makes a much lighter net as it will have around 50 less sinkers around the bottom.
Our Minorcan ancestors made two different types of cast nets, Spanish net and English net. The Spanish net was made to the desired length then an extra two feet or so was added and lead line sewn on then brought back up one half of the two extra ft. and attached to The inside of the net with brail lines forming the one ft. bag. A hand line is attached to the top of the net, when the net was cast any fish under the net would be trapped in the bag at the bottom of the net as it was hauled in. Now came the task of removing the fish from inside the bag and pending on the catch this took some time. The English was made to the desired length, and then the lead line was attached.
Then a horn made from a cow horn was attached in the top of the net. Then 16 to 18 brail lines went from a swivel that was also made from a cow horn down to the lead line and evenly spaced and attached. A hand line was attached to the top of the swivel completing the net. When the English net was cast the fisherman would pull the net in by the hand line and as the horn slides down over the brail lines forming a bag that traps every thing inside. Once the net is pulled ashore the fisherman would reach down and grab the net by the horn and slide it back up to the swivel that is attached to the hand line releasing every thing that is inside.
Thus the English net is much faster to make, much easier to rig and, most importantly much easier to remove its contents.