I have an LPL 7700 enlarger having negative carrier with only glassless inserts for full frame 35 mm (I took enlarger second hand as is). Now I started shooting 6x6 and need another negative carrier or inserts for 6x6. Checking B&H and Adorama shows that there are two options, either Universal Carrier for LPL 6700 /670 with glass (seems, 670 is the same as 7700) or glassless carrier for 6x6. As a temporary solution I print on crappy Krokus 4 enlarger with its own glass universal carrier without problems, except very annoying dust on four glass surfacess, but the negative is flat. My concerns are about glassless carrier for relatively 'big' 6x6 negative, could it keep my negatives sufficiently flat? Even 35mm negatives in glassless carriers are not really flat, anyway I get prints in focus from corner to corner. Another questions is: in case I would need a full frame print from 6x6 it will be possibly only with glass carrier, am I right? Thanks in advance for your advices.