Friction back size for 3.2ctw diamond studs

[J Peterman]

Quick question for the PS stud pros.

I’m working with DKJ on a pair of anniversary studs for my wife, ~7.5mm diamond studs in a platinum 4-prong Tiffany engagement ring style setting with double claw prongs and a flat open base, set low to help with droop.

My wife has a few other sets of earrings she wears regularly: 2 with screwbacks that she finds extremely uncomfortable, and 6mm sapphire wedding studs in bezels with the thicker 0.042” Guardian II post/larger 8mm backs which don’t droop and she finds more comfortable (but she notices the post thickness).

For this pair, I was planning to use the thinner (0.035”, ~0.89mm) Guardian II posts and large heavyweight friction backs. That way she can get the droop prevention benefit with more comfort and safety, and we can always get Guardian II backs and use a bling dot or silicone disk for even more security/support if she wants.

@yssie I have read you recommend the Stuller 24203 heavyweight concave friction backs in most cases. Would you recommend 8mm or 10mm for studs this size? I think you typically recommend the heavy 9.5mm Stuller platinum friction back (20369) on platinum posts, but I’ve read about some jewelers recommending WG backs on platinum posts to prevent sticking/binding. Either way, we need something hypoallergenic, and her earlobes are not particularly large. I was leaning towards the 8mm 24203 in 14k Palladium WG but would appreciate some pro insights from people here that actually wear these things.

Thanks in advance!

 

[yssie]

I’ve not heard of WG backs binding to platinum posts - and googling isn’t coming up with anything that seems reliable, d’you happen to have any more info?

I personally have always matched my backs to my posts and never had any problems! But to answer your actual question - I think for smaller lobes, the 8mm pad size would probably be a safer choice, and big enough to keep 3.2ctw studs nice and upright

 

[J Peterman]

Thanks so much for your reply @yssie

Here’s a link to @diamondseeker2006 post from a few years ago where some industry pros mentioned WG backs on platinum posts might be preferable:

Question for the PROS on white gold versus platinum for earring and bracelet settings

We have seen discussion on various threads regarding platinum versus white gold for pierced earring settings as well as tennis bracelet settings. I know some are curious about screw-on posts and backs versus tension backs on earrings, although I have seen multiple jewelers discourage the screw...

www.pricescope.com

 

[yssie]

Thanks so much for your reply @yssie

Here’s a link to @diamondseeker2006 post from a few years ago where some industry pros mentioned WG backs on platinum posts might be preferable:

Question for the PROS on white gold versus platinum for earring and bracelet settings

We have seen discussion on various threads regarding platinum versus white gold for pierced earring settings as well as tennis bracelet settings. I know some are curious about screw-on posts and backs versus tension backs on earrings, although I have seen multiple jewelers discourage the screw...

www.pricescope.com

Ah. Okay, a little misunderstanding.

So think about a really thick rubber band. You pull it, it stretches. You have to pull really hard to make it stretch, because it’s really stiff, but it stretches a bit. Now let it go. Goes back to its original shape.

Alloyed gold is a bit like the thickest, heftiest, hardest-to-stretch rubber band you’ve ever encountered. If you go with friction backs, every time you stick them over the post, you're pushing those curvy bits apart - going from the left pic to the right pic:

With gold friction backs - because of alloyed gold's rubber-band-eyness - for every moment that the post is forcing the curvy bits apart, the gold is trying to go back to its original shape - so the curvy bits are pressing against the post as tightly as they can. And once you remove the post those curvy bits will bounce right back to like on the left. That's just because of the way the material behaves.

Platinum has much less of that rubber behaviour. So every time you push a post through platinum friction back earrings, and you push those curves apart, they're pretty okay with staying there. They're not pressing against the post (ie. gripping the post) trying to get back to their original state the way gold does. (They are, I mean, but to lesser extent). And when you remove the posts they'll go back, but not quite as tight as they were originally. Again - just way the material behaves.


So that's all well and good. But here's the thing. In practice, in actual real life, what matters over every single other thing is how much metal there is. The thicker the metal sheets making up those curvy bits are, the harder they're going to be to move - the tighter the back will cling to the post. And the impact of increasing metal heft outweighs all materials properties mumbo jumbo by a landslide. A heavyweight platinum friction back with curvy bits made of thick metal sheets is going to grip the post *much* more tightly than a gold friction back where the curvy bits are made of thinner metal. This is so extreme that for earring backs the practical conversation can be scoped all the way down to "heavyweight or not" and you can basically just ignore metal entirely.

(I italicizied for earring backs in my last paragraph. For an eternity band with delicate prongs, say, the prong heft isn't changing - you don't have "heavyweight" and "lightweight" versions of eternity band prongs or tennis bracelet prongs! So in those cases choosing white gold over platinum makes a very real difference, and that's why many vendors prefer white gold for pieces with lots of delicate prongs. Because they want the gold to try to snap back into place if it's dislodged).


For your wife's earrings - if you decide on friction backs, just go with whatever metal you prefer and choose a heavyweight style. That's what I've done. And my preference is always to match back metal to post metal. Worst case scenario with platinum - you can just push the curvy bits back close together with your fingers and restart the stretch cycle

 

[J Peterman]

Thank you for taking the time to write such a thorough reply. It sounds like either of those heavyweight friction backs will be a good choice! I’ll start with the 8mm. Much appreciated

 

[diamondyes]

Ah. Okay, a little misunderstanding.

So think about a really thick rubber band. You pull it, it stretches. You have to pull really hard to make it stretch, because it’s really stiff, but it stretches a bit. Now let it go. Goes back to its original shape.

Alloyed gold is a bit like the thickest, heftiest, hardest-to-stretch rubber band you’ve ever encountered. If you go with friction backs, every time you stick them over the post, you're pushing those curvy bits apart - going from the left pic to the right pic:

With gold friction backs - because of alloyed gold's rubber-band-eyness - for every moment that the post is forcing the curvy bits apart, the gold is trying to go back to its original shape - so the curvy bits are pressing against the post as tightly as they can. And once you remove the post those curvy bits will bounce right back to like on the left. That's just because of the way the material behaves.

Platinum has much less of that rubber behaviour. So every time you push a post through platinum friction back earrings, and you push those curves apart, they're pretty okay with staying there. They're not pressing against the post (ie. gripping the post) trying to get back to their original state the way gold does. (They are, I mean, but to lesser extent). And when you remove the posts they'll go back, but not quite as tight as they were originally. Again - just way the material behaves.


So that's all well and good. But here's the thing. In practice, in actual real life, what matters over every single other thing is how much metal there is. The thicker the metal sheets making up those curvy bits are, the harder they're going to be to move - the tighter the back will cling to the post. And the impact of increasing metal heft outweighs all materials properties mumbo jumbo by a landslide. A heavyweight platinum friction back with curvy bits made of thick metal sheets is going to grip the post *much* more tightly than a gold friction back where the curvy bits are made of thinner metal. This is so extreme that for earring backs the practical conversation can be scoped all the way down to "heavyweight or not" and you can basically just ignore metal entirely.

(I italicizied for earring backs in my last paragraph. For an eternity band with delicate prongs, say, the prong heft isn't changing - you don't have "heavyweight" and "lightweight" versions of eternity band prongs or tennis bracelet prongs! So in those cases choosing white gold over platinum makes a very real difference, and that's why many vendors prefer white gold for pieces with lots of delicate prongs. Because they want the gold to try to snap back into place if it's dislodged).


For your wife's earrings - if you decide on friction backs, just go with whatever metal you prefer and choose a heavyweight style. That's what I've done. And my preference is always to match back metal to post metal. Worst case scenario with platinum - you can just push the curvy bits back close together with your fingers and restart the stretch cycle

Thank you so much for explaining, Professor Yssie! I always learn so much from you

 

[diamondseeker2006]

My studs are 7.6mm each and set in platinum, and even though I have some larger backs, I've been wearing them with the 6mm platinum backs that came with them with no issues thus far. You definitely do not need 10mm backs for this size stud, but I think 8mm would be great!

 

[J Peterman]

Just the kind of advice I was looking for when I started this thread! Thanks @diamondseeker2006