Printerless mode: effects and options for text output

Up to version 27, List & Label always required an installed printer driver as a so-called device context for its outputs (print and export). We have already explained the background to this in more detail in the article Why Does List & Label Need a Printer Driver?. But since version 27 of List & Label, this system dependency is no longer mandatory. This also enables new areas of application - see No More Printer Driver Dependency: The New Printerless Mode in List & Label 27.

But what can be expected when using the printerless mode and what needs to be considered under certain circumstances? A few technical background information and tips are provided below.

Resolution of the used device context

In “normal” mode, List & Label uses the selected printer driver with its resolution as device context, which is used for positioning characters/texts. As a rule, the drivers used have a resolution >= 600 DPI. In printerless mode, however, no printer driver is available (see, for example, the Docker environment) and therefore the device context for List & Label is the screen (Screen-DC). However, this screen DC has a much lower resolution of 96 DPI - sometimes only 72 DPI. Since the resolution is predefined by Windows, it cannot be influenced by List & Label. This results in a lower resolution in printerless mode, which influences the positioning of characters/texts.

Used fonts

differ greatly from one another. The settings in the font itself, such as weight (i.e. the thickness of the font - usually “bold”) or the point size, are also factors that can lead to deviations - the smaller the point size of the font is set, the greater the possible deviations in the positioning/output of the characters.
Unfortunately, no general recommendations can be given for one or the other font; it always depends on the use in the present report. We have achieved good results in tests with Tahoma or also Verdana with a set option LL_OPTION_VIRTUALDEVICE_SCALINGOPTIONS of 600. However, the display cannot be free of deviations in direct comparison with the printer driver rendering of List & Label with, for example, the Microsoft XPS Document Writer.

Objects for text output: Simple Text object vs. Formatted Text object (RTF)

In List & Label reports, formatted text objects (RTF) can be used in addition to simple text objects with individual paragraphs. However, the effects on the text output in printerless mode are partly different.

Simple Text objects

With the simple text objects, List & Label can technically only influence the rendering to a limited extent. To control this from the point of view of the respective application, the scaling option LL_OPTION_VIRTUALDEVICE_SCALINGOPTIONS already mentioned can be used. But also the use of differently scaling fonts in a lower resolution/DPI environment can have a positive effect on the positioning.

Formatted Text objects (RTF)

The formatted text objects (RTF) have a special position, especially in printerless mode, because List & Label itself has no technical influence on the rendering and scaling of the texts. The background to this is that List & Label always sets the RTF control from Microsoft that is present on the underlying Windows system and uses this for rendering. List & Label cannot influence in detail what happens to the texts and the scaling of the fonts used when the lower screen DC is used in printerless mode. The only thing that can be influenced is the version of the Microsoft RTF control that List & Label should load and use for rendering the texts - see further details in the article General Information for the RTF Object.

In general, however, it can be said about the fonts that especially the spacing between the individual characters can be positively influenced by certain fonts and thus the overall typeface is improved. The font ‘Arial Unicode MS’ is only conditionally suitable for formatted text objects (RTF) in printerless mode, as the spacing can be very wide, especially in bold mode. Here too, Verdana or Tahoma are clearly better suited in terms of display in a direct comparison.

Due to the technical challenges and differences in text presentation mentioned above, it is therefore always necessary - especially for existing reports with a familiar and desired appearance - to carry out checks as part of a conversion to Printerless mode and, if necessary, to make adjustments to the layouts in the Designer (see Used Fonts or also to the scaling options provided (see also LL_OPTION_VIRTUALDEVICE_SCALINGOPTIONS).