Illustrator / black gap between objects

Try to reasume. There is some problem with sampling and it have to be improved in some update, yes? i fixed the problem with stretching rectangle, fortunettly S didn't have this problem and there is no gap. U think Adobe will solve it?

Which format you export and which export option you use?

Don't overlap edges to prevent anti-aliasing:

That might not work because of the gradient.  I wonder if Pathfinder > Intersect would work.  The gradient may cause a problem.  The other option would be to nudge the two anchor points to the left ( .001" ) to close the gap.  Then Group the two elements.

Try Pathfinder > Merge on the upper and left part and the adjoining gradient rectangle ( select both using the direct-selection tool ).  If that does not work, use Pathfinder > Unite or Pathfinder > Add to Shape.

Remek,

Also applying to the S and possible other troublesome letters, you may consider/try a few other ways:

A) Use the (new) Freeform Gradient (you can read on here, especially first link also linked to here, this also applies to B)),

Search Results

Create gradients in Illustrator

B) Use stroked paths with a Gradient along the stroke, you may calculate the % where the actual gradient is to start (you can just use two stop, one white where the white part ends and one black at 100% or 0% depending on the direction.

C) Create and hide copy of the filled path on top, then apply the gradient to the original (for the E you can use a horizontal gradient effective both at top and bottom, then show and select the top copy and remove the part that covers the gradient part of the original.

It's the result of antialiasing.

If the antialiasing method Supersampling doesn't improve it, your only chance is to make the rectangle larger or overlay another object.