Printing ^, ~ and _ in ZPL

^XA
^CF0,40
^FO40,40^FD2^10 = 1024^FS
^FO40,120^FD10~20 kg^FS
^XZ

This prints 2 and 10, and nothing else. The printer takes ^10 and ~20 as commands it does not know, and the rest of each field goes with them.

When the data comes from people, it can be worse: a value containing ~JA cancels everything waiting to print.

^XA
^CF0,40
^FO40,40^FH_^FD2_5E10 = 1024^FS
^FO40,120^FH_^FD10_7E20 kg^FS
^FO40,200^FH_^FDPART_5F0042^FS
^XZ

• ^FH_ before ^FD says the field holds hex escapes, each an underscore followed by two hex digits.
• Write ^ as _5E, ~ as _7E, and an underscore itself as _5F, since under ^FH a bare underscore starts an escape.
• ^CC and ^CT can change the command characters instead, but they change them for everything that follows. Escaping the field keeps the fix where the problem is.

Send this body to POST https://api.zeepler.com/v1/zeeplify with your API key in the x-api-key header. It is a working request, not an illustration: on every change, our tests run this same file through the API's code and compare the result with the ZPL below.

1{
2  "config": {
3    "size": "4x2"
4  },
5  "data": {
6    "formula": "2^10 = 1024",
7    "range": "10~20 kg",
8    "part": "PART_0042"
9  },
10  "templates": [
11    {
12      "type": "Text",
13      "dataPath": "formula",
14      "coords": [40, 40],
15      "font": "0,40"
16    },
17    {
18      "type": "Text",
19      "dataPath": "range",
20      "coords": [40, 120]
21    },
22    {
23      "type": "Text",
24      "dataPath": "part",
25      "coords": [40, 200]
26    }
27  ]
28}

And the ZPL that comes back, ready to send to the printer:

^XA^MCY^XZ
    ^XA
    ^SZ2
    ^MMT
    ^MNY
    ^LL406
    ^PW812
    ^LH0,0
^CF0,40^FO40,40^FH_^FD2_5E10 = 1024^FS
^FO40,120^FH_^FD10_7E20 kg^FS
^FO40,200^FH_^FDPART_5F0042^FS
^XZ

Send the values as they are. zeepler escapes ^, ~ and _ under ^FH in any field that has them, so they print and never run as commands. A field without them goes out unchanged.

• Call the API from your own server or integration engine, not from a web page. An API key in a browser is a key anyone can copy.
• A successful call answers 200 with the ZPL as plain text. A request the API cannot turn into a label answers 400 with every problem listed by field, and is not billed.
• Send the ZPL to a Zebra or other ZPL printer at 203 dpi. At 300 dpi the same label prints at two-thirds of the size.

The API reference has every field and status code.

• QR code size in ZPL: How ^BQ magnification sets the size of a QR code, and how to work out the size in dots.
• Font size in ZPL: Setting text height with ^A and ^CF, converting points to dots, and why ^CF carries over.
• Send ZPL to a Zebra printer from C#: Send ZPL from .NET to a network printer on port 9100, or to a USB printer through the Windows spooler, without the driver redrawing it.