Version: FMS and FMP 21
System: Win 10
Problem: I have a simple POS receipt that takes longer to print than I like. There is often a delay of several seconds between when I hit “print” and the receipt prints.
I discovered the theme was “Classic” and changed the theme to “Minimalist”.
Question: Does Minimalist have the same potential performance issue that Classic has?
Minimalist theme is going to be the perfect start for printing.
Be sure to set the default text object to the most common font before copying it for bold, or different sizes.
Akso make sure that no other object uses the Classic Theme and then remove the Classic Theme from the file.
There is a "document" about the Classic Theme on Claris site that explains why it should be avoided, but I just can't find it 
. @Malcolm , do you know the document I am talking about ? Maybe you have it's address.
Are you referring to Top-Tips-Optimizing-Performance-of-FileMaker-Custom-Apps-in-the-Cloud?
There are a bunch of tips, including "do not use local styles" and "use a modern theme instead of classic theme".
How about this Claris Community Thread where some guy called "Planteg" referenced https://support.filemaker.com/s/article/FileMaker-Pro-17-Advanced-release-notes.
Planteg wrote:
This document - see FileMakerPKB https://support.filemaker.com/s/article/FileMaker-Pro-17-Advanced-release-notes - stated that the Classic theme was specifically created for IWP and then deprecated with the introduction of WD. The theme was made to work well in an HTML context, not FMP/A context.
Beverly responded:
In fact the Classic theme does NOT work with Web Direct. This is the biggest issue that we ran into for many clients. Those that had to use Classic for IWP and upgraded to use WD. Fortunately most of the layouts were as lean and mean as possible, so just a few gotchas appeared when changing to Minimalist theme, for example.
There seems to be several PDF versions of the Top Tips article I linked at the top of this post. The text in the PDF is different to the text in the online article and various problems with Classic theme are expressed in differently in each.
Top Tips: WebDirect_071320_final (older)
Top Tips: final_rev (current)
That does not see to be the one I am looking. The one I would like to find explains that the Classic Theme was created for IWP, and that this theme should not be used again because it may corrupt the file.
This was quoted by Clay Maeckel, I think, at one of the developer conferences in Sydney.
Rob
Good article on how to convert off Classic theme. I've used this on literally hundreds of layouts a few years back......
Is there really a relationship between the theme (classic in this case) and the print speed to a POS receipt printer?
Is the printer USB / Wifi / Ethernet / Serial?
Potentially. Depends where and how the rendering is performed and passed to the printer. I don’t have enough knowledge of that to say more.
The printer is a Bluetooth TSP700 ( a common receipt printer).
My POS (which I did not build) is fairly well designed, but dates back at least 20 years. There are four files (Interface, Data, Reports, and Printing). The original developers updated much of the structure, but the Printing file seems to be the most archaic and has many layouts based on the Classic theme. I suspect that accounts for 80-90% of the receipt printing problem. (I can print from the Reports file to a wireless laser printer without delay.)
Therefore, I am rebuilding the receipt layout in the Interface file. I’ve tested this updated structure, and the receipts are printing much faster. In most cases the delay is negligible. Occasionally, there’s a slight delay I will attribute to the Bluetooth connection or server lag. (I am in Oklahoma and the server is in Virginia.)
I’ll try PSOS and see if that has any affect on print speed.