ERROR_WRONG_LABEL when trying to print wireless using Android Brother Sdk for label printer

I resolved this by creating a LabelInfo object, since you have a Label Printer. It's not clear at all in the documentation. You need to set the label info after the printer info.

PrinterInfo info = myPrinter.getPrinterInfo();
info.paperSize = PrinterInfo.PaperSize.CUSTOM;

LabelInfo mLabelInfo = new LabelInfo();
mLabelInfo.labelNameIndex = 5;
mLabelInfo.isAutoCut = true;
mLabelInfo.isEndCut = true;
mLabelInfo.isHalfCut = false;
mLabelInfo.isSpecialTape = false;

myPrinter.setPrinterInfo(info);
myPrinter.setLabelInfo(mLabelInfo);

The ERROR_WRONG_LABEL means that you have a wrong value in paperSize or labelNameIndex. I have a P750W label printer with a 24'' paper. I found that value 5 is the good one for this size, but I don't know for your printer.

I had the same problem and figured out that you should specify the labelNameIndex field to the PrinterInfo object. I had the QL-810W printer. I tried many values and nothing worked until I set it to:

   printerInfo.labelNameIndex = LabelInfo.QL700.W62RB.ordinal // -> 17

I figured out the correct value by making a for loop with all integers from 0 to 100 and logging the result until the printing succeeded with this value. I know this is not the optimal solution but I can't find any documentation or reference for these codes.

Here is the code I used to specify the PrinterInfo object:

    val printerInfo = PrinterInfo()
    printerInfo.printerModel = PrinterInfo.Model.QL_810W
    printerInfo.port = PrinterInfo.Port.NET
    printerInfo.orientation = PrinterInfo.Orientation.PORTRAIT
    printerInfo.paperSize = PrinterInfo.PaperSize.CUSTOM
    printerInfo.align = PrinterInfo.Align.CENTER
    printerInfo.valign = PrinterInfo.VAlign.MIDDLE
    printerInfo.printMode = PrinterInfo.PrintMode.ORIGINAL
    printerInfo.numberOfCopies = 1
    printerInfo.labelNameIndex = LabelInfo.QL700.W62RB.ordinal // -> 17
    printerInfo.isAutoCut = true
    printerInfo.isCutAtEnd = false
    return printerInfo