What is this called and how to do it?

[Inky Doc]

I bought an 89 cent screwdriver and a small box of furniture tacks. Next I hacksawed the screwdriver where the metal post meets the plastic handle. Then heated the sharp point of one of the tacks and then buried it to the head. Problem solved, total cost about $2.50. 

[gigi]

I think those are not bubbles, those are depressions (optical illusion). Done with a Pear-Shader (tilted) or similar stamp maybe.

Edited February 21, 2017 by gigi

[cjartist]

1 minute ago, gigi said:

I think those are not bubbles, those are depressions (optical illusion). Done with a Pear-Shader (tilted) or similar stamp maybe.

I second that opinion.  There doesn't seem to be a unified pattern there like you would expect from a stamp.

[Tugadude]

2 hours ago, Inky Doc said:

I bought an 89 cent screwdriver and a small box of furniture tacks. Next I hacksawed the screwdriver where the metal post meets the plastic handle. Then heated the sharp point of one of the tacks and then buried it to the head. Problem solved, total cost about $2.50. 

Nice idea but that isn't going to get you where you want to go.  The pear shader is probably the answer.  Most of the depressions are similar and some seem to be "siamese twins" next to one-another.

[Inky Doc]

They are indeed depressions. The tool I made recreates the effect quite nicely. I've only messed around with it for a few minutes but was able to easily make the different nuances that are displayed in the pic at the top of the thread. I also guessed that someone more skilled than I accomplished the same with a smooth pear shader. 

[Logans Leather]

looks like a smooth pear shader twisted randomly between each strike

[glockanator]

On 2/10/2017 at 9:05 AM, Inky Doc said:

I'm wanting to know how to do that bubbly-looking effect.  Also, I'm assuming it is simply block dyed after its tooled. Am I correct? 

Edit: the larger "bubbles" are the subject of my question  

Thank you kindly. 

That looks like a Duane Ballard piece. He is a super cool dude just email him and ask. I would be surprised if he did not answer you.