Paste code or load the sample — the result appears below, with the line and severity of each finding.
2Result
Health report
The layout is intact — nothing clipped, nothing resized — but
everything sits lower or further right than designed, or one text line floats
above where it should anchor. Shifts have four file-side suspects, they
stack, and each has a different fix.
^LH — the label home
^LH30,20 moves the origin of every field: a field at
^FO50,50 actually lands at 80,70. It exists so one template can
be nudged for stock with a pre-printed margin — and it bites when a template
written for that stock travels to plain labels. If the whole layout is offset
by one constant amount in both axes, look for ^LH first.
^LS — the horizontal shift
^LS slides the whole label left or right, and it accepts
negative values. Its classic use is centring a narrow layout on wider media;
its classic failure is a leftover value pushing content toward one edge —
horizontal-only offset, vertical untouched.
^LT — the top offset, applied by the printer
^LT moves the whole label up or down relative to where the
printer believes the label starts. An honest tool note: our preview
recognises ^LT but does not simulate it — the structural check
lists it as a command the renderer does not apply, so the on-screen position
deliberately ignores it. Vertical-only offset with clean ^LH
and ^LS → check ^LT, then the printer's own
top-position setting.
^FO vs ^FT — the one-field shift
When a single field sits wrong while the rest align,
the position command is the suspect. ^FO anchors the
top-left corner of the field; ^FT anchors the text
baseline — the same coordinates produce text roughly one character
height apart. A template mixing the two looks aligned in the author's head
and staggered on paper. Pick one convention per template.
When it is genuinely the printer
If the file carries no ^LH/^LS/^LT
and uses one position convention, a drift that varies label-to-label — or
grows down the roll — is physical: the media sensor finding the gap late, or
media loaded loosely. That is calibration and mechanics; a constant,
repeatable shift is almost always one of the four commands above.
Frequently asked questions
Why does my whole ZPL layout print shifted by a constant amount?
A constant shift in both axes points at ^LH, which moves the origin of every field; a horizontal-only shift at ^LS; a vertical-only one at ^LT or the printer's top-position setting. A drift that varies label-to-label is physical — sensor or loosely loaded media.
Why does one field sit wrong while the others align?
Check its position command: ^FO anchors the field's top-left corner, ^FT anchors the text baseline — the same coordinates differ by roughly one character height. Templates mixing the two print staggered; use one convention per template.
Does the preview apply ^LT?
No — the preview recognises ^LT but does not simulate it, and the structural check lists it as a command the renderer does not apply. The on-screen position deliberately ignores it; the printer applies it at print time.
