The white spots could be caused by very small water droplets when the coating is sprayed onto the mugs.
This used to be a common problem when spray painting. Water can build up in the air compressor & then this is forced out of the system through the spray gun. This used to be a big problem in such places as car body shops but, they now use filters in the lines to trap the water. You'd be amazed at how much water you can get out of an air compressor tank at the end of the day.
The reason why you can't see the faults is because the water droplet becomes solid as it is partly mixed with the coating & then pops with the heat.
I've had the odd few just the same at the very start but, now know who the good suppliers are. I buy my mugs from someone on Ebay & I haven't had one faulty mug off him yet. The last lot I bought off him the other day & the price was £65 for 72 mugs inc delivery.
I've just bought 10,000 orca coated 10 oz mugs, were based near Milton Keynes, if anyone wants any, they can have them for 95p each, vat free and collect them, these are A grade, not the cheap rubbish that we've all had to buy recently. Lets get together and stop lining the pockets of the cheap import sellers, just drop me a line.
Were talking quality, not cheapness, anyone can get cheaper, i can get mugs for 40p each, but what's the point, unless you want the grief that some of the people on here are getting.
Don't want to step on your toes, sorry, obviously you're doing very nicely out of the site.
Oh dear! I was praising the person I got my mugs off in my last post. I've just had a delivery & the new mugs have arrived in two of the poorest flimsiest boxes I've seen. I opened the first box took out a mug & it was cracked & chipped. It also looks like the two chips inside the mug had been stuck back on very badly.
So, looks like my wonderful mugs are now very much like the poor quality none of us want. Looks like I'll now be looking for a new supplier.
Most of our mugs are for Motor sport and Equestrian, we get top dollar for them, but they want quality, that's the reason we've worked our way through the poorer quality mugs, all i wanted to do was get people through the hassle we've had in the past, it's not nice, especially when all your hard work ends up in the skip.
Same with printers, it took us 3 years of blockages and wasted ink to get away from the Epson's, now we use Ricoh, and my advice to anyone doing mugs on a small to medium scale is buy the e3300, will cost about £280 complete, on my first set of cartridges we've done 1200 mugs without one blockage or paper jam.
Mugs are only a small part of our business, embroidery and print are the main stay, anyone want a straight answer to a question, just ask, we've been through just about every problem going, that's why i'm not too diplomatic with suppliers, theyre only out for your pound at the end of the day.