This is the most common source of problems. A lot of failed wall vinyl jobs are caused by lack of understanding of different types of vinyls and laminates by printers. You can’t just use ANY cheapest vinyl and expect it to perform well on every single surface!

Avery and 3M DON’T give warranty for any of their vinyl applied on painted drywall because each wall has a unique combination of texture, paint and primer used and it is close to impossible to clean painted drywall compared to such surfaces as glass and metal. Because of these factors the same vinyl can behave absolutely differently on two seemingly similar walls. 

• Don't use REMOVABLE VINYL for any wall graphics! From our experience, it is hard to do any “temporary” jobs on painted drywall. The temporary adhesive vinyl will very likely either be not sticky enough and peel or on the contrary stick too much and damage paint when removed. Using removable vinyl for wall will cause the graphics to peel around all the edges, will cause bubbling and other bad results.
• Use high quality PERMANENT or car wrapping CAST VINYL for long term application. For permanent application the rule of thumb is to choose the stickiest product in your arsenal. For less sticky products the results are better when using thin cast vinyls with thin laminates like 3M IJ180 with 85 series laminate (our preferred material for "forever" graphics).
• Don't expect any calendared thick vinyl to last long. Even vinyl that is technically "permanent" but is calendared and thick (4mil to 8mil thickness) will eventually start to shrink and will cause edges lifting and peeling badly. This vinyl is good for up to 1 year as a rule. 
• Laminate your prints. Cost cutting by not laminating vinyl leads to premature edges peeling, ink fading, scratches during installation, very costly removal process. 
• Don't use calendared laminate on cast vinyl! if you laminate premium vinyl like IJ180 with cheap thick laminate it will ruin all great features of the vinyl. 

This is a common headache for us. Wall murals printed too short or too long are a big cause for reprints for our clients.

• ALWAYS DO A SITE CHECK! Site checks are essential to measure the wall and make sure the finish of the wall is adequate for the vinyl. Never print anything based on architectural drawings! They are always different from actual dimensions. 
• Include BLEED. Doesn't hurt to mention it twice. Add 1" all around for smaller graphics, add 2" all around for big graphics like mall hoardings. 
• Measure wall height in several spots. It is very important for older buildings. We've seen often height difference of 2"-4" between the beginning and the end of the wall. 
• Keep an eye on doors, outlets, thermostats etc. Make sure you don't place text or other important design elements over a door frame, handle or an outlet. It will look bad. 

In many cases vinyl printed for a job can't be used because it has issues with size, overlaps, bleed, color etc. Here we will give only some examples because the variety of issues is really too big to write about every case we've seen. 

• INCLUDE BLEED AND OVERLAP. This is very simple. Unless we ask specifically not to include bleed in super rare cases (elevator doors for example) there must be around 1" bleed on all 4 sides for any graphics. There also has to be 0.5"-1" overlap between panels. This can vary depending on the job but can't be skipped. 
• ALWAYS PANEL GRAPHICS VERTICALLY! It is tempting to print a W200”xH88” piece as two horisontal panels but it will be the biggest mistake you can do. It is close to impossible to match long horisontal panels.
• No crop marks should be printed on the graphics. Crop marks are acceptable on the taglines.
• Leave taglines showing panel number or mark the panels in a different way. We can't be dealing with a 500 sq.ft. jigsaw puzzle of vinyl pieces on site! 
• Check your panels side by side for alignment and color-matching. Do this before shipping! Although fairly rarely we see one panel printed shorter than the one next to it or color doesn't match at the seam. Sometimes every other panel needs to be rotated in RIP software to avoid this. 
• Check your print quality before shipping vinyl! Seriously, pay attention to banding, stuff trapped under laminate, ink drops on vinyl, pixelation, color accuracy etc. Somehow a lot of people in production don't think it is their job to notice these things.