How to make @page size work on small sizes

Question

When using @page size, I can't make it display in preview to low sizes. For example, I have this @page size values:

@media print {
    @page {
        size: 2.5in 4in;
        size: landscape;
        margin: 0;
    }
}

.printable {
    text-align: center;
    border-style: solid;
}

I get this:

Even if I change to 3.5in x 4in or 4in x 6in, that's consistently the size I get. Is there something I'm doing wrong or am I missing something or is this just not possible (low sizes).