Hello @ACS2018 thanks for your post. I feel your pain when it comes to creating and printing barcodes, especially if they are for single or one-up items. Let me tell you my approach and maybe something here will be of help to you. I know these options are not a fast track easy way, but once I setup the master file it has become easy for me to make edits or create new barcodes.
If you have page layout software with the capability to use barcode "fonts":
I do all my barcodes manually, meaning I don't use any Square Retail barcode printing function. I have some page layout programs that help a great deal (Adobe InDesign) but I know a lot of people don't have this, so you may be able to use Word or another program. If you have the software and experience, you can layout labels to fit a sticker paper and use a font to generate the barcode.
If you don't have or want to use layout software:
I first started with this site onlinelabels.com. They have a barcode generator tool that makes you a graphic. You can cut and paste that into any place you can print labels. I also buy my price stickers from them, and use a template to place these barcodes into. Again, it takes a while to figure out what kind of barcode works best for you; some limit character counts, and others may not work with your barcode scanner so will need to be tested.
One idea I have is if you do a lot of one-up singular items, you could do a bulk sheet of unique labels. This is where you'd create a whole lot of barcodes at once, for example sake calling them BAR1, BAR2, BAR3, BAR4, etc. Then create your barcode sheet filled with these unique labels. Then when you go to create a new inventory items, click on the SKU field in your Square dashboard, and then input or scan one of the premade barcodes into that SKU field. Then attach that barcode sticker onto that item. Maybe if you premake a whole sheet of barcodes like this, then adding that into new item SKU wouldn't take so much time when you actually want to add an item.
You could also try this...there are preprinted barcode or asset tag labels you can purchase, like these ones. I have no idea if they will work with your barcode scanner, but if they would you could purchase a bunch of these and then scan into the SKU field as I mentioned above. Just be sure to check on the kind of adhesive these labels use; some are permanent, and depending if you're placing this on a plastic sleeve or actual comic cover, pay attention if the label is removable. This would save you from even dealing with layout and printing of barcodes for all of your individual unique items/collections. The downside is the barcode numbers would have no special meaning for you; like if you make your own you can use prefix the COM to denote comics, or NOV to denote Novels, etc.
You also mentioned that the lack of barcode printing limits putting items online for sale? I know adding inventory to the websites isn't easy either, and for me takes learning a certain routine as well. If I do a bunch at once, I can get into a rhythm and it goes rather quickly. I think you'd be able to add website items without adding a barcode or SKU, especially if your items are only one unique collection.
I hope maybe something here may help you. I've found it's all about developing a system that works for you. I know it's mostly manual workarounds at this point, but I've come to appreciate the flexibility it gives me sometimes.
