Can't keep head of plate clean.

[lwelch39]

Running Toko 4700, conventional fountain, black ink, can run 5,000 or so, bond paper, then ink starts bleeding over top end of plate into image area... add water and it washes out, can't find a balance after first 5,000 run.

 

[Bill Borcicky]

There are different things to look for, first I would check all your rollers if the stripe is on the heavy side(wide) it could cause this. Another thing to check is your amount of ink on the rollers. Some pressmen run the water a little heavy an run the ink a little heavy to compensate. There is a fine line of getting water and ink set just right. it may be possible to drop your water down a little more and your ink.? Finally, I would check the position of the image, if you had to drop the image down by moving the plate cylinder, you may have to make a new plate with the image lower on the plate itself. If the top of the plate cylinder is too low on the blanket cylinder ink will deposit over time at the top of blanket and be printed on your sheet. The longer the run the more it will transfer and farther into your image area it goes.

 

[Offset George]

We run 10 % alcohol in our fountain solution to minimize water to the plate. Alcohol makes water wetter so you use less. Running minium water you can use minimum ink but still get nice dense coverage. Position of plate to blanket as Bill Borcicky mentioned is also a possibility. Check your PH and add a small amount more of what ever fountain concentrate you are using. Make sure your ink has the proper tack to help pull it off the plate and of course make sure your ink roller setting and water are within specs.. On our large presses we run 20 % alcohol..

 

[ziggy33]

most people are getting away from running alcohol at all on their presses