A pattern number and dye-lot or "run number" is printed on each roll. A pattern number identifies a particular design and color way of a pattern. The dye-lot number represents a particular group of rolls that are printed on the same print run.
Different dye-lot numbers could signal variables such as a possible tonal change of color, because the batch of ink to print one run of wallcoverings may appear different due to temperature of surface, humidity in the air, a replacement print roller, or the like. Reflectivity may be a result of a new batch of vinyl coating. A replacement embossing roller may change somewhat the texture and embossing efect.
Because of this, it is very important to check each individual roll in your wallpaper job to ensure uniformity in color and pattern. You must also buy enough wallcovering at the same time so you do not run out. It is also important to record pattern numbers and dye-lot or run numbers in case additional rolls are needed to complete a project. They will often be available is given to your supplier when you reorder.
Assume your run number or lot number is "23D38" and you run short. You and your dealer have 4 choices.
- Run number "23D38" Only - if not available you must decide what to do next if you underordered.
- Run number "23D38" If Possible - if not available the supplier will give you another random run.
- Any run which is a bad idea because any run will come in and probably will not match what you have already
- Run number "23D38" or best match - which means your dealer must ask for the run only and if not available mail off an unpasted sample you bring in. Most dealers will charge extra for this special service, if they can provide it at all.
The best idea is not to under buy the first time. Accurate room measurements are important.