As with all things handmade, there will be any number and variety of less-than-perfect results.  The good news is that there are very few dry plate oops!'s that can't be salvaged.  You can crop — either with a mat or in the enlarger or with Photoshop.   And, you can be flexible with your printing methods.  A good plate can be scanned, photographed, enlarged,  or contact-printed, but your options may be reduced with under- or over-exposed plates. 

Don't be reluctant to 'spot' a plate.  It was an accepted part of photography in days of yore.  Tiny bubbles that can sometimes dry in the emulsion can be dabbed with black or sepia watercolor paint (undiluted, with very small brush.)  The small, white mark that will result on the print can then be spotted with photo dyes.

And, last but certainly not least, you can celebrate the uniqueness of handcrafted art and print from border-to-border.

'Accommodation', the plate shown at the top of this page, was coated while the emulsion was still too warm.  With a puddle pusher and emulsion well I have best luck coating at 33C-35C on room temperature glass.  This time, I was in a hurry and I guessed (poorly) at the temperature.  The emulsion in the center of the plate is perfect, but it pulled back from the edges.  Fortunately, for subsequent plates, it was just a matter of waiting a few minutes for the emulsion to cool down.  Usually, I use 'oops!' plates for exposure testing, but this time I knew exactly what I wanted to do.  I had just found the barnacled bottle the previous evening and I decided the medium fit the subject. 

Bottom line: This plate, as ugly as the edges are, is still useable.  If nothing else, it can be cropped — either in the enlarger, with the Photoshop 'crop' tool, or by selectively matting a contact print.  

The most common problem I have is unevenly coated plates.  The plate below was made with the last dregs of an emulsion batch.  I was pretty sure there wasn't enough to cover a whole 5x7 inch plate, but I wasn't about to throw away perfectly good emulsion.  Sure enough — and no problem. While I was loading the dry plate into a holder, I noted the emulsion pattern (you can load color-blind and orthochromatic plates under a safelight, so there's never a doubt about the condition of a plate's coating).  Then, I drew a 'map' of the pattern on a Post-it and stuck that to the outside of the dark slide.  When it came time to expose the plate, I composed the scene to match the emulsion.  Remember, what you see through the ground glass is upside down, so orient the plate accordingly.