The second method can be a graphic object such as image or a rectangle, or text. More error correction codewords improves the reliability of the barcode.
At the final step when the PDF file is created, the values are converted to text strings. Path is either a string or System.
If your data can be divided into segments with just digits or just alphanumeric characters you can create a QR Code object with array of data strings. Input string with 13 digit and a leading zero is considered UPC-A.
Therefore, the specimen do not necessarily need to be sectioned, but require coating with a substance such as a heavy metal. The information is kept in memory except for images and embedded files.
This was closely followed in with functioning commercial instruments, and in with Gerd Binnig, Quate, and Gerber's invention of the atomic force microscopethen Binnig's and Rohrer's Nobel Prize in Physics for the SPM.