Pits in Mugs

[JSR]

I've never read of anyone else having this issue but I can't believe it's just me.

For quite some time now, I've noticed that regular 10oz (RN Coated) mugs exhibit various degrees of pitting in their outer surface.



You can't see these pits until you've printed the mug but then they show up as bold white dots. When you look really close, you'll see dimples in the mug where the white dots are. The white dot is caused because the paper can't touch the surface of the mug where the dimple is (I'm guessing the dye-sub coating is also missing from that area because otherwise *something* would transfer).

When you look at the transfer paper after taking it off the mug, you see a matching dark spot where no ink has transferred (the same kind of thing you get when you have an air bubble).

I've tried switching suppliers (more than once) but all I end up with is an ever increasing pile of wasted mugs.

Does no one else have this problem? If not, where do you buy your mugs?

[accdave]

Not noticed it on any of mine. Get mine from BMS usually.

[jennywren]

I don't have mugs from BMS ( that is NOT meant to be disrespecful ) and have never had pits, If you switched suppliers it just seems unlikly that it would happen from all of them, (not in less they all buy from the same suppliers.) It would seem sensible to buy from BMS as they had a recommendation. When I've had a few mugs that seemed iffy my supplier offers me a credit note, you can only ask, any good supplier I'm sure will offer that at least.

[Andrew]

I go through a lot of mugs and you do very occasionally see a pit mark on a mug. Even then most of the time the gas process still takes to a certain extent and doesn't leave a clear white spot as in yours. Perhaps the pitting is making the coating bubble on that spot which will not then take the ink. They are very prominent white spots. Might have just been a bad batch but would be surprised if you get that often with the main suppliers.

[John G]

I've had a few mugs from lovecut that have pits on them but the print always seems to cover them.

Cheers John

[bms]

I think the pits/ spots are caused by dust in the factory that sprays the coating on the mugs. If the factory is dusty then the air borne dust particles stick to the surface of the mug and "pop" during the drying time, leaving a minute section uncoated which causes the spot when printing.

There are grades of sublimation mugs in the marketplace - A's, B's and C's. The C grades are grey/ white, straigh(ish) if you're lucky and lots of pitting. The B's are better and the A's the best (although I think it's almost impossible to guarantee no pits in hundreds of thousands of mugs). All mugs should be inspected prior to packing at the factory by the manufacturers, but the quality process depends a lot on who's checking what.

The main sublimation mug suppliers buy from only a few manufacturers in the Far East (China or Thailand) but there are hundred's of manufacturers of mugs for sublimation printing with almost as much variation in the mug size, thickness of ceramic, straightness, quality of coating etc etc!

[JSR]

Thanks all for your replies.

I think fate just has it in for me, that's all. I must attract the iffy-mugs like a magnet.

[AJLA]

I had a terrible problem from a batch I bought from somewhere, they weren't pitted but there were areas where the coating clearly hadn't covered the mug.
Shame you've had some bad batches.
I'm sticking with my BMS mugs as they have been far more consitent on quality for me.

[GoonerGary]

These pin holes drive me crazy. Unfortunately there is no perfect supplier and each one will have their quality issues. Perhaps a quiet word in the manufacturers ear?

[Andrew]

Where do you get your mugs from GG? This isn't that common a problem and shouldn't happen ongoing.