How I Select The Pattern And Shape For A Cabochon

[bobby1]

When I'm preparing to cut a cab I look at the rough for a distinctive pattern that I want to include or feature in the cab. With this slab of Brazilian Agate I wanted to include the mountain-like image on the upper right as well as the red and black lines. My next objective is to estimate how big the cab could be. I have a personal preference for larger cabs because I can utilize much more of the patterns in the rough. Because I don't generally make my cabs for sale I can make them as big as I want. Also, because I display my work at gem and mineral shows I find that bigger cabs show better.
Here is a photo of the rough for this cab.

I have sketched a rough outline on the slab shown in the next photo. One of the most important things in designing the cab is to exclude fractures, pits and soft areas that won't  polish. The outline also helps me to visualize the possibilities for the shape. Often the shape of the rough "talks" to me (what a dorky statement) about the shape that is in the rough. I often use concave contours to eliminate the defects. I also use convex curves to eliminate defects.
The outline assists me when I use the trim saw to remove unwanted material.

Here is the final product. It is 3" on the longest side.

I hope this has been helpful. I will be posting more discussions as I do more cabs.
Bob

[travelerga]

Bob, my rocks talk to me also. I ont feel dorky unless they comment on my choice of hats or sandles.lol I talk back to mine too. I also let the stone tell me how it wants to be cut and somtimes I have to cut out a feature I want to keep .just to balance the stone.
mike

[Taogem]

Bob,

That would be great if you posted more of your cabbing processes..

I am pinning this thread so maybe you can keep adding to it?

If that is ok?

If not and you would rather start a new one each time then I will know next time you share one of your cabbing processes..

[bobby1]

I can just keep adding to this post for now if that's OK with you.
Bob

[The Polished Pebble]

I agree, when you study the stone - there are many choices. But, the stone will dictate what you do.

I don't do calibrated stones for that reason. I just seems wrong to me to just layout ovals, rounds or other standard template designs to get the most out of the slab.

Don't get me wrong, if the design in the stone can be framed by a standard design - great! But more often than not, there is always something that I want to have in the cab that just doesn't fit. Or there is a fracture or pit that I swear came out of nowhere.

I think I drove the person that tried to teach me how to cab nuts. LOL, He was one that thought all cabs had to be standard sizes & such. Always getting the max out of every slab. Most of his cabs, while quite nice, were just that - cabs.

Connie

[Bluesssman]

Bob, I am looking forward to more of your discussions on this topic. One thing, however, I have learned is you can not let the stone talk on and on and on. It happened to me and I did not want to be rude, but after three days I'd had enough!!!



Gary

[mirkaba]

Good discussion Bob! Freeforms are surely the best way to go with most rocks. I find that even though I  start out to cut freeform I usually end up sliding back to geometric shapes of some sort. More commonly an elipse or teardrop shape but occaisionally a somewhat pleasing form slips in. Lately I have been playing with form and more symbolic shapes and patterns. Keep your posts coming! You do excellent work.....Bob

[cal]

Bob, I hope you don't mind if I have some fun.
I looked at this piece when I first opened the thread and did not scroll any further past the first picture until I had decided what shape I would use and what features I would use.

I certainly love what you did with the free form idea and had not thought that was what you were going to do.

I just had some fun and said to myself what would you do Cal.
By the way a great piece of agate.

My thought was to do this


I really like what you did and think it turned out fantastic.
It shows you I have to think more outside the box.

[bobby1]

Cal,
Taking the pattern that you selected and expanding it more to the side and upward it would have been a notable pagoda scene, also. The possibilities in any material are well beyond what we indicated. I like it when people expand their vision beyond the ordinary shape and patterns. It makes cabbing really interesting.
Bob

[Bluesssman]

I am drawn to free forms and A symmetrical shapes. Perhaps it is because I do not see symmetry in nature or perhaps it is because I am a little off center. Isn't it wonderful we all do not see the world the same way!

I really enjoy seeing how others interpret patterns and shapes. Thank you Bob and Cal for sharing your visions!



Gary

[ozbod]

Yes, I use a similar process to that you described, my templates now sit in a drawer in the workshop.

Now that I have started working with Labradoroite more I feel I need the freedom on not using set shapes in prder to capture the labradoresence as much as possible.

Cheers

Dave

[bobby1]

I find that templates (I have many, including drafting templates) can narrow your vision of the possibilities in the material, can help define a specific feature, can expand your vision as you reposition it on the rough and can open your mind to the endless shapes of your imagination.
Bob

[Mark]

Gary, did you whack that stone to get it to shut up?  I got boxes full of talking stone that I need to get the upper hand with.  Most are not very nice and are usually taunting me.  I think they listen to my wife too much and think they can push me around.  I must admit I am a templater.  I know its a dirty word, but I tend to be more symetrically oriented.  I occasionally go free form and sometimes that's all you can do when you don't have the space for a templete cab.  I often go freeform when a preform breaks during trimming or grinding.  I then will change the shape to still be able to use the cab.  My wife who is really artistically inclined, hates it when I fix a broken preform, she says it looks like I screwed up and am trying to fudge it.  Well, I am, but often they look really nice and I am happy with how they turn out.  And who wants to waste good stone?  Actually my favorite shape is not symetrical, though it is in the new templates.  It is sorta like a claw, if you have seen my cabs you will have seen it.  I probably only use 5 or 6 patterns and don't like the square or rectangular shapes much.  I usually stick with my claw shape, tear drop, oval, circle, shield, and kite shapes.  I figure that I will turn into a freeformer when I start to cab the leftover boxes in about 400 years.  Good thing I am a vampire and will live forever, otherwise I would never get to the freeformer state.  That's probably why I'm not a woodworker and instead concentrate on stone, a loose stake to the heart and your a gonner, while stone can't hurt me, just taunt me.  God I hope nobody ever reads these posts and gets the idea to put me away.  I'm not crazy, just a bit mental, too much work and too many thngs to think about.  Mark

[cal]

Mark, reading your posts makes me laugh
Thank You

[Mark]

Oh, that's nice. Laugh at the poor demented guy.  Only kidding.  If we can't laugh at our situations, we're surely doomed to short lives.  Good thing that I will never grow up, no matter how much my wife wishes it.  I'm still addicted to video games like a kid and watch cartoons with my kids all the time.  Some of my favorite shows are geared to pre-teens, go figure.  My excuse is that I have to think so hard at work to write and test computer software, that I have to be a brainless boob around the house to keep my sanity.  I am so fried lately, that I can't hardly add 2 + 2 anymore.  Maybe its just early senility.  Mark