4Brains Labs · from 4Brains Technologies, Navi Mumbai

Practical guides to QR codes, word clouds, image cut-outs and 3D-print engraving

Written by Sanjeev Shankar Sinha and Alok Kumar, the co-founders of 4Brains Technologies, around the four free tools on this site. Each guide works through one job, from sizing a QR code for a poster to numbering a batch of 3D prints, and ends with a checklist or a short summary you can work from.

Read the guides The four tools →

Latest guides

All 9 guides →

Image cut-outs · Method
Product photos on white: full-size cut-outs, and where they fail
What full resolution means in a cut-out, how one becomes a square listing image on pure white, and three measured tests of where automatic cut-outs go wrong.
10 October 2026 · 9 min read
QR codes · Reference
How big does a QR code need to be to scan?
The real answer is module width, not code width: where the distance-divided-by-ten rule comes from, when it breaks, and minimum print sizes in millimetres.
25 September 2026 · 11 min read
QR codes · Reference
QR codes for a printed menu that do not stop working
Why a dynamic QR code can kill 200 printed table tents at once, when it is still the right choice, and how to print one that nobody can switch off.
25 September 2026 · 11 min read
QR codes · Reference
Which barcode symbology you actually need
The map through EAN-13, UPC-A, Code 128, ITF-14, Data Matrix and the rest: what each one is actually for, and why a retail number has to come from GS1.
25 September 2026 · 10 min read
QR codes · Method
UPI QR codes for a small business: what to print and what to check
What a UPI QR code really contains, when to bake in an amount and when not to, and the four-minute check that stops a printed counter code failing at the till.
25 September 2026 · 10 min read
3D-print engraving · Design
Engraving a logo into a 3D print without losing the detail
Artwork prep for an engraved logo: the thinnest stroke a 0.4 mm nozzle holds, when to redraw the mark instead of shrinking it, and when paint rescues it.
25 September 2026 · 9 min read

Four subjects, four tools

Every guide is about a job one of these tools was built for. The tools are free, need no account and add no watermark.

QR codes and barcodes

How big a code has to be for the distance it is scanned from, why a dynamic code on a printed menu can stop working, what a UPI payment code really contains, and which barcode a product or a shipping carton needs.

QR Studio makes all of these in your browser and puts the content in the code itself, so there is no redirect that can expire.

What it does →Open QR Studio

Word clouds

Turning hundreds of free-text survey answers into one honest picture, and the choices of shape, typeface, colour and density that keep a word cloud readable on a poster and on a phone.

WordCloud Studio pours your words into a shape in your browser and exports a PNG up to 16K or a vector SVG.

What it does →Open WordCloud Studio

Image cut-outs

Taking the background out of a photograph at the size it was taken, and knowing in advance where automatic cut-outs go wrong: fine hair, glass, thin wires and subjects that match their background.

Product photos on white: full-size cut-outs, and where they fail

Background Remover runs a segmentation model on a graphics card on our own server and returns the cut-out at the resolution you uploaded.

What it does →Open Background Remover

3D-print engraving

Engraving a logo into a 3D print without losing its detail, and numbering a production run with serial numbers that stay readable once the layer lines show.

4B Engraver cuts a logo, name or serial number into your STL or 3MF on our server and returns a watertight 3MF and an STL for your slicer.

What it does →Open 4B Engraver

How the tools are run

Built for real jobs first

Every tool here started as something we needed on a real project, such as engraving serial numbers on a batch of printed parts or making artwork for a brand activation. The guides cover the same jobs.

Free, paid for by ads

QR Studio and WordCloud Studio run entirely in your browser, so using them costs us nothing. Background Remover and 4B Engraver run on our own server. The pages carry a few ads, which pay for hosting, so nothing is behind a paywall.

Your files stay yours

QR Studio uploads nothing you type, and WordCloud Studio stores a design only if you sign in and choose to save it. Background Remover keeps a photo in memory only and discards it once the cut-out reaches you. 4B Engraver deletes uploaded models automatically after 7 days.

Practical guides to QR codes, word clouds, image cut-outs and 3D-print engraving

Latest guides

Product photos on white: full-size cut-outs, and where they fail

How big does a QR code need to be to scan?

QR codes for a printed menu that do not stop working

Which barcode symbology you actually need

UPI QR codes for a small business: what to print and what to check

Engraving a logo into a 3D print without losing the detail