Here is what I would recommend. Before you make the purchase, go to the distributor and have them walk you through everything you have to do to print white ink on 10 shirts. Offer to pay them for their time and consumable costs to do this because it is well worth the learning lesson. This includes the following steps:
1. Take a graphic or photo that you are likely to get from someone walking around the mall. This is not going to be a professional created graphic. It will either be straight from a camera or will be something that they created in a very basic program (i.e. Paint, Word,) and is usually a flatten file without a transparent background.
2. Make sure you see what you have to do to get the file ready to print (i.e. make adjustments to colors, delete any background, add text to personalize the file per the customer's desire,...).
3. Then have them show you the process of pretreating shirts from start to finish. Then you actually do the pretreating on shirts. Time how long it takes to pretreat 10 shirts. This includes the spraying time, spreading the pretreatment with a brush / roller / squeegee and curing the pretreatment. Find out what paper(s) they recommend you use to cure the pretreatment. Calculate the cost of the pretreatment, other supplies and labor. You might want to also have your employee try pretreating some shirts as well. This will show how the difference between two people doing the pretreating will affect the quality of the shirts. This is why some of us refer to it as the Art of Pretreating and why the automatic pretreating machines are becoming more popular.
- Note: Pretreating can be a messy process. Thus, you are not going to do this in your Kiosk. You will need to do this somewhere else and then store the shirts in the kiosk. But this will require you to make sure you pretreat the proper brand, style, color and size of the shirts that the customer wants. Plus, you have to make sure that you pretreat the area where the design is going to go (i.e. front center, front left chest, back, sleeve,...). This is a ton of variables.
4. Then have them show you how to send the job to the printer. Calculate how long this process takes before you can even print the graphic (the processing or ripping time).
5. Calculate how long it takes the file to print. Please note if you are required to hit the print button between passes. When dealing with onsite production, you are bound to get questions asked or have to do something that will prevent you from standing over the printer so you can hit the load button as soon as it is available. So plan on there be some extra time in a real sales environment.
- Make sure that you print all 10 shirts so you can see if there is any issue of ink stravation. It is really easy to print 1 shirt and make it look good. Much harder to print all day and not have any issues.
6. Make sure that they give you actual figures on the cost of ink to do a job either from the RIP or weigh the cartridges / waste tank after running a series of 10 prints to calculate the average cost per print. This will help to show you how much more ink is used when printing white ink on shirts. It is more than double.
- Note that all Epson printers will do periodic spitting of ink into the maintenance tank. Add in the cost to doing nozzle checks and head cleanings, you will see on average that you will want to add 15% - 20% additional for ink lost to the cost per a print.
7. Have them walk you through the process of curing all ten test shirts. Notice what the time, temperature and pressure is for the heat press. You will need this information when you go to do your production.
8. Then have them show you how to properly clean your machine (daily, weekly,...). Keeping the printer properly maintained is a key to printing white ink! Failure to do this could cause the entire printer to be shut down - which means loss sales in a retail environment.
9. Then, go home and wash all 10 shirts. The odds are that for most people... some shirts look good and others will not be as good. That is because laying the pretreatment down must be the same or you will get different results. This is why I recommend doing 10 shirts so you can see how the results can differ.
After going through this process, you will have an accurate idea of the amount of time and expense you will go through printing dark shirts. You still will probably not have a clue as to the true amount of maintenance and tech support the white ink will cause... but this is a good start. There are plenty of posts from users that state they started off with white ink because they thought they needed it, but later decided that they don't want or can't deal with the problems associated with white ink.
In a mall environment, you want to be able to provide the customer with a shirt in a matter of a couple of minutes so you can move on to the next customer. Turnover is much more important in this setting because you are going to be doing lower runs (probably one-offs) and will need to start working on the next sale as soon as possible. Since the process of printing white has too many variables that cause you delay or a misprint, I don't think it is as profitable as printing CMYK in a retail / mall environment. It will not look good when you are in your kiosk and you are removing and flushing the print head / damper right in front of your customer.
These are just some of the reasons why I believe CMYK is cheaper, faster, easier and is less likely to cause problems for your business model. Please ask others that do dtg printing as well to get their opinions and compare them to the sales person that wants you to buy the printer.
I am not against white ink printing. I think with the right business model and the right operator(s), it can be very successful and profitable. But based on what you described as your business model and that you don't have any existing dtg printing experience, it is not in your best interest to start printing white ink. Once you add white ink to a printer, it becomes more of a craft or art to printing rather the method.
Hope this helps.