Hi,

a topic that is discussed several times is to implement bleed margins.

With 1.3 Page Margins are implemented. I believe that is is simple to duplicate this functionality to add a second group of margins.

In printing, bleed is printing that goes beyond the edge of where the sheet will be trimmed. In other words, the bleed is the area to be trimmed off. The bleed is the part on the side of a document that gives the printer a small amount of space to account for natural movement of the paper during guillotining, and design inconsistencies. Artwork and background colors often extend into the bleed area. After trimming, the bleed ensures that no unprinted edges occur in the final trimmed document.
Bleeds in Europe generally are 1mm to 5mm depending on print companies specific demands and size of product. Most common in Europe and parts of Asia is a bleed area of 3mm per border/edge. A standard DIN A4 format of 210mm x 297mm is usually extended with 6mm (3mm each) to 216mm x 303mm. Bleeds in the US generally are 1/8 of an inch (0.125" or 3.175mm). A standard Australian bleed is 5mm.

I think it is a necessary feature for a lot of users that use it for printing. Of cause you can set up guides yourself in no time and Inscape has a plugin for it integrated (printing marks). I believe it is crucial to adapt this functionality to the core features. At least for dynamic changes. If you set up guides manually or generate them by the plugin there is no chance of change them afterwards. You have to edit them manually. For example you work with a company for ages and use bleeds they told you. Then you have a reason to switch to another company urgently (e.g. the print shop is working at full capacity and you are under time pressure because you need the items as an express order at short notice. The other print shop uses different values for trimming). If you can now set these guides in the document settings or pages tool, changes can be made in seconds and makes exporting easier. So you could set the bleed to 5mm by default and export with 2mm or 3mm as needed. The exported document will be cropped to the respective bleed. This also works the other way around: if you usually use 2mm bleed, you can also extend it to larger values like 3mm if needed. The document itself is not changed, but the dynamic guides define the output area. As additional option I recommend optical clipping rendered objects to bleed's boundaries as well if wanted. As design aid you should be able to clip contents to bleed areas as well as pages even they are much bigger. This helps for non-destructive editing.

Minor: Defining PDF boxes as containers in SVG (like defs rect) for different export formats:

• The MediaBox is used to specify the width and height of the page. For the average user, this probably equals the actual page size. For prepress use, this is not the case as we prefer our pages to be defined slightly oversized so that we can see the bleed, the crop marks and useful information such as the file name or the date and time when the file was created.
• The CropBox defines the region that the PDF viewer application is expected to display or print. The TrimBox defines the intended dimensions of the finished page. Contrary to the CropBox, the TrimBox is very important because it defines the actual page size that gets printed. The TrimBox equals the CropBox.
• The BleedBox determines the region to which the page contents needs to be clipped when output in a production environment. By default, the BleedBox equals the CropBox.