Flags are generally hung from the side and are rectangular in shape.
For military banners, the country of origin would have been displayed as a section or on the canton.
Banners were hung from the top and side. Prior to the War of the Roses they often had shaped tips to the side, either pointed, swallow tail, square, rounded or double pointed.
After the War of the Roses up to modern times they are normally square in shape.
Gonfalons were hung from the top only and were used hung against a wall or as a standard, where they were seen from one direction only. For this reason the design is on one side only. Like the early banners, they can have various shaped tips at the bottom, either rounded, pointed, swallow tail, square or ??????.
Gonfalons would not have had the country marked.
Household pennants during the War of the Roses were hung from the top and side and were up to 3ft tall by 12 ft long, normally with a swallow tail.
The country of origin would have been displayed as a section or on the canton. The illustration shows bands for mottos.
Ships pennants were hung from the side only as they were run up a line on a ship. Full size they measured up to 3ft tall by 24ft long and were tapered to the tip. The country of origin would have been displayed as a section or on the canton. I will make these to half size, ie 18 inches by 12 ft long. See the picture of the "Mary Rose" with a number of pennants flying.
Small pennants up to 1ft tall by 4ft long are hung from the side only.
Small pennants would not have had the country marked.
Authentically banners for royalty and other nobles were done in silk using appliqué for the larger devices with details painted on. Those for poorer individuals would have been done in linen until the introduction of cheap cotton and these will have had large charges appliquéd on and then had detail painted on.
I will normally make banners from cotton material, because they are more robust and affordable. I can quote if you want something made in other materials.