By overlay do you mean as in a desk lamp with the green or tan glass with white glass on the inside?
That's different from slag....and I am not so sure it wasn't intended to be a satin finish.
I know way that you could permenantly make it shiny, but you could always wax it. It would add some shine temporarily...but the heat of the lighted lamp would soon remove any wax.
Linda C

The Handel overlay is overlayed with Metal.
This glass started its life with a sheen...in between the metal overlays and on the edges the glass is still shiny.
I have tried wax and it does help but I hoped that perhaps someone knew of a specialized glass polish made for this sort of condition. Thanks for your input.

Then it was likely metal polish from some well meaning former owner that caused the glass to become abraded.
What a shame!
Linda C

Just on a hunch...I checked the MAAS website & they indicate MAAS works on glass & crystal. I swear by MAAS as a polishing agent for metal but, personally, I've never tried it on glass.

I'd contact MAAS & see what they have to say?

/tricia

Here is a link that might be useful: MAAS

I don't think metal polish is the culprit because the metal is still in possession of its full patina.
I think instead of a damp cloth someone, without a clue- used some sort of abrasive chemical on it.
It is glass so there should be a way to fix this. Frankly, if I didn't have another art glass lamp in the same room no one would notice the difference.

I will try the MAAS website.

Thanks to all.

Kathleen

I have two lovely glass lamps I am certain of 1934 or before, because they were a wedding gift to my parents-in-law from one of their aunts. They are shaped like vases, and have painting or decal work on them with brass handles and brass or some other metal base.

Like your's, the glass was very matted looking and dull. I was afraid to use anything too strong to clean them, for fear of damaging the decals or paint on the glass, but they were so cruddy looking I was to the point I didn't care. Someone had also hand painted over the brass with gilt paint and it was a kill it or cure it situation.

I took acetone to them. and they cleaned up like a whistle and are shiny again. Simple nail polish remover. I am not saying I recommend you do this, but the dulled finish was really nothing more than seventy five years of dust and grease apparently turned hard. Down the road, I intend on rewiring them to use as lamps again.

I don't know how you would test to see if this woud work without risking damage if there are any painted parts.

I am not aware of any chemical capable of etching glass but hydrofluoric acid or some of the very, very caustic fluoride compounds. Nasty stuff and dangerous. I can't see somebody using it to clean a lamp. Some gritty abrasives surely could, but I doubt it's a chemical etch.

And if someone had put an abrasive chemical on the glass, wouldn't it have ruined the patina on the metal work?

That's what I was thinking, Linda. The patina would be destroyed whether the cleaning compound was grit or chemical, unless the glass could have somehow been separated from the metal parts. I am not at all familiar with this type of lamps, so I don't know what I'm talking about in that respect.

The patina is fully intact. In fact, that is what makes this such a mystery to me. The patina on this almost hundred year old lamp is in very fine condition. In examining the shade closely you can see that someone was very careful when they dulled the glass not to touch the patina. And where they stopped the shiny glass starts.
The metal overlay does indeed have some painted parts but they are on the bottom portion of the glass and are not affected.
I have been speaking to a glass artist who was recommended by a local auction house. He told me to try ammonia...which I did. No difference. I will try it again and perhaps try some nail polish remover on the inside of the shade (which, by the way is mostly shiny...telling me that this dullness was not caused by over firing the glass in the kiln in order to bend the panels to fit the lamp). So I will continue my hunt. I suppose if someone used an abrasive (like Comet) I could probably wax the glass to bring back some of the sheen.

From what you are telling me, it was meant to be that way.
There was a lamp much like that on my desk when I was a teen ( my mother gave it to her cleaning lady because she thought it was ugly!) so I know the metal overlays you have. Perhaps the chemicals they apply to patinate the metal causes a matte finish on the glass?
I suggest going to shops and looking at similar overlay lamps, Handel and Miller and whatever else you find and look to see the degree of gloss on the glass.
Linda C

I have seen many Handel metal overlays (Teroca) and none of the ones I have seen have this condition. Inside of the lamp shade some of the glass panels are shiny and some are dull. There are run marks where the dull ends and the shiny glass starts. The glass artist I contacted said that the glass was either meant to be this way or it was over fired . I was thinking that perhaps this shade was involved in a fire. Although there are painted parts on this lamp which are fine and original the way Handel used to get the paint to adhere to the glass was by baking the shade after it was painted. So I would expect them to be fine even if the lamp was involved in a fire.
This is the only thing that makes any sense to me.
So far I have tried ammonia, acetone, paint thinner (I certainly did... on a small area on the inside of the shade on a panel which faces the wall), white polishing compound (which gave the shade a very slight sheen) and I have ordered some MAAS metal polish...thank you for the link triciae. Nothing removed the dullness so I really don't feel like it is dirt. But what do I really know. My nana was a teenager when this lamp was made and my mother wasn't even born. LOL.
After all is said and done we still enjoy this beautiful lamp every night. It looks fine when turned off and looks stunning turned on. I am happy to have it. I may just have to get over the dullness.

You can take out panels clean with warm soapy water and soft texture dish scrubber. Let dry and carefully seal glass with clear lacquer. Totally acceptable.

Wow!!! 11 years later...another comment!