Your Flood Bar

The Flood Bar: The Most Overlooked Tool on the Press

In screen printing, everyone talks about mesh counts, squeegee durometers, off-contact, tension, and ink shear — but the flood bar rarely gets the spotlight. Truth is, the flood bar is one of the simplest pieces of hardware on the press, yet it has an outsized impact on ink performance, opacity, and print consistency.

A good flood sets up a great print. A bad flood creates problems before your squeegee even touches the mesh.

Below is a deep technical dive into the flood bar: how it works, why it matters, and the practical tricks that will immediately improve your prints.

What the Flood Bar Actually Does (and Doesn’t Do)

The flood bar does NOT print.

Its job is simple:

1. Fill the stencil with ink

   This means rolling the ink on top and into the stencil gasket so that when the squeegee makes its pass, the ink has a clean, complete supply ready to shear through the mesh.

2. Condition the ink for shear

   A good flood shears the ink slightly — optimizing ink flow and preparing the deposit for a smooth print stroke.

3. Level the ink body

   A flat, even flood prevents roping, pinholing, and inconsistent coverage.

4. Keep the open stencil area flooded (mainly water-base inks)

   The flood bar can be set to “flood-out” to keep the open stencil area of the screen completely flooded to prevent dry-in.

Flood Bar Best Practices

1. Use a Flood Angle of 10°–15°

A flood bar set too vertical will dig into the mesh and push ink through the screen prematurely.

Too flat and it will glide over the ink without filling the stencil.

Ideal:

A gentle forward tilt — just enough to push the ink across the stencil without pressure.

2. Light Pressure Only

Your flood bar should barely kiss the screen.

You are NOT printing here — you’re simply laying a blanket of ink. More pressure means less ink deposit. Your flood bar should not rest on the mesh — you should see a sliver of light between the flood bar and the mesh. This gap allows ink to flow underneath, producing a nice even deposit.

Too much pressure can:

• Drive ink through the mesh (ghost printing)

• Wear out emulsion and mesh faster

• Create thin or dry spots in the flood

• Pull your image out of registration

Tip: If ink drips through the stencil during the flood, your pressure is wrong.

Exception: For thick, sticky special-effects inks, putting the flood bar closer to the mesh can help “scrape” ink across the surface.

3. Always Flood to the Open Area

On autos:

Leave enough space between the flood end point and the top/bottom of the art. Never stop the flood inside the image — it leaves lines and disrupts peel-away.

To maintain a full flood:

• Use tight screens that don’t sag

• Keep a healthy amount of ink in the screen so weight helps ink fall and flow under the bar

On manuals:

Only flood enough to keep the stencil filled and hydrated (especially with water-base).

4. Match Flood Speed to Ink Type

High-viscosity inks (white plastisol, HD, shimmer, FX bases):

Slower flood helps pre-shear.

Low-viscosity inks (waterbase, discharge, hybrid):

Faster flood prevents over-shear and dripping.

Rule of thumb:

Thicker ink → slower flood

Thinner ink → faster flood

Tricks & Pro Tips the Manuals Don’t Teach

1. Set your flood bar to hover

   You should be able to slide a couple business cards under the bar when it’s down.

2. Use winged flood bars

   Unwinged bars are rarely an advantage anymore.

3. Wipe the flood bar with base or softener

   Helps release ink and makes cleanup easier.

   For WB: a water/softener mist works.

4. Do NOT over-flood on waterbase

   Too much pressure or dwell causes:

   
   

   • Premature drying

   • Dark stencil spots

   • Weeping edges

   
   

5. For Special Effects (HD, Rock, Sculpture, Puff)

   Use:

   
   

   • Slower flood

   • Slightly firmer pressure

   • Bigger ink wave
     
     

   
   

6. Avoid Dry Mesh

   If the flood doesn’t cover the entire print area, expect:

   roping, grainy coverage, chatter, premature mesh wear.

7. Use an Ink Tender

   On WB jobs, an ink tender can top off ink and scrape ink back into the open stencil area.

Dialing in the ‘Ink Wave’

The bead of ink in front of your flood bar tells everything.

The wave should be:

• Smooth

• Even width

• ~½ inch tall (plastisol)

• ~¼ inch tall (waterbase)
  
  

Too small: stencil starvation

Too big: ink dumps over stencil edges

When to Double-Flood

Double flooding helps if you’re:

• Printing thick whites on fleece

• Using shimmer, glitter, HD

• Working with cold or stiff ink

• On borderline screen tension

• Wanting a smoother second stroke after flashing

It increases dwell time, warms ink, and improves flow.

The Flood Bar as a Diagnostic Tool

If your flood looks bad, your print will be bad.

Watch for:

• Skip marks

• Thin spots

• Gaps

• Uneven waves

• Ink trapped under the bar

• Pressure lines

Any of these warn of issues with:

• Tension

• Off-contact

• Ink viscosity

• Screen damage

• Poor reclaim

• Dirty bar edge

The flood bar is your early warning system.

Final Takeaway

The flood bar is essential to ink control, opacity, and consistency.

A perfect print starts with a perfect flood.

If the flood is wrong, the print stroke becomes a rescue mission.

Dial it in, keep it clean, watch the wave, and let the flood bar set the stage for a smooth, clean, efficient print.