To get good overall coating, you coat larger than final size and then cut after dry. I would leave at least 10 mm extra to both sides. Then, your initial cut does not matter much and can be approximately done with scissors etc.
Originally Posted by Athiril
For example, coat 150 mm wide material and get two strips of 120 film at the same time. Or, coat 120 mm wide and get one 120 and one 35mm strip. Many options here, but I wouldn't bother trying to coat a pre-cut material because of the problems of emulsion leaking out or not filling the whole substrate. Really, it depends on the coating method, but if you coat larger than final you have ALL the coating options available. Most of them (blade, puddle pusher, etc.) rely on the fact that the coating apparatus slides on the top of the very same substrate, meaning that an uncoated area is left over.
For example, if you use a coating blade, 150 mm substrate and 130 mm blade would yield an usable coating of 120 mm quite easily, I think.
It's also nice to get more film at one coating. OTOH, If you try to coat too wide, it starts to get harder, but I think this is not a problem until 200-300 mm.
Many ways to cut, one of the easiest is to place sheets of wood/plastic/metal/anything with straight edges near to each other to form small gaps between them to guide a knife such as a box cutter.
250 mm material would be quite optimum for coating 8x10 sheets. You could coat 2-3 sheets at a time and then cut them separate.
Last edited by hrst; 05-10-2012 at 07:40 AM. Click to view previous post history.