Hollow liners, let's dig in and break these down a little. These were always the trickiest of groupings to make myself, they always took a lot more care, attention and planning to build and solder, but I always found it worthwhile as they are a super effective grouping to line with. Faster, less trauma, and make crisp DARK lines with ease.
What you do to make them is remove the center pin in a round grouping. For example, a hollow eight is a nine-round minus the center pin, and a hollow six is a seven-round minus the center pin. You are effectively maintaining the exact width of the larger grouping and minimizing the force needed to push it into the skin. Additionally, the grouping has a void in the center, allowing it to carry more ink and saturate the line more efficiently. Sounds easy, right? Not really. I used to have very specific soldering jigs in use to make hand soldering these easier. Fortunately, now we have developed specific fixtures with our manufacturers to streamline this process and reproduce them perfectly and consistently.
First, we produce two types of hollow groupings, a tight hollow and a loose hollow. I'll explain why.
Tight Hollows are produced by arranging the pins in a perfect circle with the center pin left out, as previously mentioned. The grouping is then tightened before finish soldering. This draws the points of the taper closer together, flexing the middle portion of the pin slightly outward. What this achieves is a tight grouping for precise lining that still maintains the efficiency of less force required and crisp lines, similar to any normal tight grouping you may be used to, yet producing less trauma to the tattooed skin.
Loose Hollows are produced in a similar manner, yet the pins are left straight, similar to a round shader or straight liner. By building them this way, we allow the natural taper of the arranged pins to create the overall taper or point of the grouping. These make nice bold dark lines with ease.
This helps dispel a bit of the mystery of how and why we make Hollow Liners and the advantages of their use.