Render, generate and print labels. With a single library.

One package instead of four

One NuGet package for four jobs

Many .NET teams buy several SDKs just for labels: a ZPL emulator, an EPL emulator, a label designer and a barcode library. zplCore.com covers ZPL rendering, EPL rendering, label design and barcode generation in a single assembly.

Platform & cloud

Runs wherever your backend runs

Docker & Kubernetes

Dockerfile and Helm chart included

• All tests pass in the official .NET 10 container images for Debian and Azure Linux 3.0.
• Dockerfile.server included: distroless image, runs without root privileges, with a /health endpoint.
• Helm chart for Kubernetes included. You build the image yourself; it is not published to any public registry.
• No extra system packages required; the NuGet package ships the native libraries.
• Stateless per renderer: a web service scales horizontally.
• Asynchronous ASP.NET Core minimal API sample with a job queue (199,000 labels/s ZPL generation on a Mac).

FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
WORKDIR /src
COPY . .
RUN dotnet publish samples/WebApiDemo -c Release -o /app

FROM mcr.microsoft.com/dotnet/aspnet:10.0-azurelinux3.0-distroless
WORKDIR /app
COPY --from=build /app .
ENTRYPOINT ["dotnet","WebApiDemo.dll"]

kind: Deployment
spec:
  replicas: 2
  template:
    spec:
      containers:
        - name: label-api
          resources:
            requests: { cpu: 500m, memory: 512Mi }
            limits:   { cpu: "1",  memory: 1Gi }
          readinessProbe:
            httpGet: { path: /health, port: 8080 }
---
kind: HorizontalPodAutoscaler
spec:
  metrics:
    - type: Resource
      resource:
        name: cpu
        target: { type: Utilization, averageUtilization: 70 }

Code

Three lines to a preview

var renderer = new ZplRenderer(new ZplRenderSettings { Dpi = 203 }.WithLabelSizeMm(100, 150));
List<byte[]> pngs = renderer.ProcessCommands(
    "^XA^FO50,50^A0N,40,40^FDHello World^FS^BY2^FO50,120^BCN,80^FD12345^FS^XZ");
renderer.Settings.OutputFormat = ZplOutputFormat.Pdf;
File.WriteAllBytes("preview.pdf", renderer.ProcessFile("labels.zpl")[0]);

using ZplCore.Labels;
var job = PrintJobTemplate.FromFiles("templates/leading.json", "templates/shipping.json", "templates/trailing.json");
job.JobName = "Tour 7";
job.KeyField = "TrackingNo";          // first/last key on the trailing label
job.CutAfterLastLabel = true;        // cut only after the last label
job.StoredFormatName = "R:SHIP.ZPL";  // template once, then field values only
string zpl = job.For<Shipment>().ToZpl(db.Shipments.Where(s => !s.Printed).Take(50).ToList());
File.WriteAllText("job.zpl", zpl);     // 52 labels in ONE file

# samples/WebApiDemo – ASP.NET Core Minimal API
dotnet run -c Release --project samples/WebApiDemo
# Stream 50,000 shipments from EF Core/SQLite as ZPL
curl 'localhost:5080/api/jobs/db/zpl?country=AT&take=50000' -o at.zpl
# PDF preview from JSON records
curl -X POST 'localhost:5080/api/jobs/preview?format=pdf' -H 'Content-Type: application/json' -d @records.json -o preview.pdf
# Asynchronous via the queue: 202 Accepted, 429 when full
curl -X POST localhost:5080/api/queue -H 'Content-Type: application/json' -d '{"db":{"country":"AT","take":20000},"output":"zpl"}'

var epl = new EplRenderer(new ZplRenderSettings { Dpi = 203 });
List<byte[]> labels = epl.ProcessFile("label.epl");
string zpl = epl.ToZpl(File.ReadAllText("label.epl")); // migrate EPL forms to ZPL

var bc = new ZplCore.Barcodes.Barcode
{
    Symbology = ZplCore.Barcodes.Symbology.Gs1_128,
    Code = "(01)09521234543213(10)LOT42",
    Unit = ZplCore.Barcodes.BarcodeUnit.Millimeter, BarWidth = 0.33, BarHeight = 20,
};
File.WriteAllText("gs1.svg", bc.ToSvg());

FAQ

Frequently asked questions