TRIMMED VS. UNTRIMMED WALLPAPERS
Most Thatcher digitally printed wallpapers are provided trimmed (or "pre-trimmed"). Your wallpaper is trimmed if no selvage edge is included — the pattern extends all the way to the edge of the paper. With digital printing there is no need to include a selvage edge for aligning the pattern in the same way as is required on screen printed wallpapers, therefore most modern wallpaper rolls are made pre-trimmed to save a step during installation
Most screen printed wallpapers are provided untrimmed. This means that when you unroll the wallpaper, you will see that there is a blank area on the left and right sides of the wallpaper. This is called the selvage edge, and it is approximately 1.5” on each side. This will need to be trimmed off prior to installing the wallpaper. Your selvage edges are clearly marked with what are called “trim join” marks. If you do not see a selvage edge or trim join marks on your roll, you have pre-trimmed wallpaper.
Untrimmed, our wallpaper width is 30”. Once trimmed, our wallpaper width is 27”.
Trim join marks are placed exactly in between the pattern edge and the selvage edge of the wallpaper. The purpose of trim join marks is:
- To define the exact place to line up the pattern repeat with the next drop of wallpaper
- To define the exact place to trim the wallpaper along the selvage edge
Why Are Some Thatcher Wallpapers Untrimmed?
Most traditional screen-printed wallpaper is provided untrimmed. The reasons for this are many.
Valuable Information: Selvage edges provide a space for the trim/join mark, which allows the installer to quickly determine the pattern repeat and match.
Superior Installation: Many installers prefer to trim their own selvage edges. It provides them with more control when matching the wallpaper seams. Are you working with an installer who does not like to work with untrimmed wallpapers? This likely means that they lack experience with untrimmed wallpapers. Check in with the WIA, your designer, or Thatcher, to find an installer with experience with untrimmed wallpapers.
Damage Prevention: The most common way a roll of wallpaper is damaged prior to installation is by being dropped on its end. When a roll of wallpaper is dropped on its end, the paper gets smashed and it can ruin the roll. This risk is significantly reduced with an untrimmed roll, since a damaged end is simply trimmed and discarded.
Trimming wallpaper is an extra step, and most wallpaper installers will assign a small upcharge for this service. However, the extra step provides superior results and superior craftsmanship.
Table Trimming vs. Double Cutting
Table Trimming: This is the process of laying out the wallpaper along a horizontal flat work surface (such as a table) and trimming the selvage edges off using a sharp razor prior to hanging. We recommend this method for most installations, because it is considered less risky.
Double Cutting: Some wallpaper installers specialize in what is called double cutting. That is when you do not pre-trim the wallpaper on a table, but rather you hang two drops of wallpaper on the wall, overlap them, and trim both at the same time on the wall, and pull off the selvage while the wallpaper is wet. For some installers, this is their specialty and they prefer it, having ample experience and success with this method. If this is the case, then you should trust that your installer is choosing the best method for your installation.
DIYers: There are a lot of YouTube videos that offer tutorials on how to hang untrimmed wallpapers using a double cutting method. We recommend table trimming, NOT double cutting for beginners.
If in doubt as to which trimming method to use, we suggest table trimming. The major risk with double cutting is that you can cut through the wall surface below the wallpaper, causing serious damage to the wall and the installation.